diff --git a/src/musredit_qt6/mupp/PmuppGui.cpp b/src/musredit_qt6/mupp/PmuppGui.cpp
index 3dfe724a..5ea584a7 100644
--- a/src/musredit_qt6/mupp/PmuppGui.cpp
+++ b/src/musredit_qt6/mupp/PmuppGui.cpp
@@ -1082,7 +1082,7 @@ void PmuppGui::addX(QString param)
   if (!param.isEmpty()) {
     // check that param exists
     if (fParamList->findItems(param, Qt::MatchCaseSensitive).empty()) {
-      QMessageBox::critical(this, "**ERROR**", QString("Parameter X '%1' not found").arg(param));
+      QMessageBox::critical(this, "ERROR", QString("Parameter X '%1' not found").arg(param));
       return;
     }
     paramName = param;
@@ -1125,7 +1125,7 @@ void PmuppGui::addY(QString param)
   if (!param.isEmpty()) {
     // check that param exists
     if (fParamList->findItems(param, Qt::MatchCaseSensitive).empty()) {
-      QMessageBox::critical(this, "**ERROR**", QString("Parameter Y '%1' not found").arg(param));
+      QMessageBox::critical(this, "ERROR", QString("Parameter Y '%1' not found").arg(param));
       return;
     }
     paramName = param;
@@ -1141,7 +1141,7 @@ void PmuppGui::addY(QString param)
 
   // make sure that any x-parameter selection is already present
   if (fViewX->count() == 0) {
-    QMessageBox::warning(this, "**WARNING**", "It is compulsory to have at least one x-parameter set\nbefore trying to add a y-parameter.");
+    QMessageBox::warning(this, "WARNING", "It is compulsory to have at least one x-parameter set\nbefore trying to add a y-parameter.");
     return;
   }
 
@@ -1150,7 +1150,7 @@ void PmuppGui::addY(QString param)
   if (idx == -1)
     return;
   if (fXY[idx].getCollectionTag() != fColList->currentRow()) {
-    QMessageBox::warning(this, "**WARNING**", "x/y parameters need to originate from the same collection.");
+    QMessageBox::warning(this, "WARNING", "x/y parameters need to originate from the same collection.");
     return;
   }
 
@@ -1338,7 +1338,7 @@ void PmuppGui::check(QString varStr, QVector<int> idx)
     }
   }
   if (count == idx.size()) {
-    QMessageBox::information(this, "**INFO**", "Parsing successful.");
+    QMessageBox::information(this, "INFO", "Parsing successful.");
   }
   fVarDlg->raise();
   fVarDlg->setFocus();
@@ -1750,7 +1750,7 @@ void PmuppGui::dropOnViewY(QListWidgetItem *item)
   if (fViewX->count() == 0) {
     fViewY->removeItemWidget(item);
     delete item;
-    QMessageBox::warning(this, "**WARNING**", "It is compulsory to have at least one x-parameter set\nbefore trying to add a y-parameter.");
+    QMessageBox::warning(this, "WARNING", "It is compulsory to have at least one x-parameter set\nbefore trying to add a y-parameter.");
     return;
   }
 
@@ -1826,7 +1826,7 @@ void PmuppGui::createMacro()
 
   QFile file(fMacroName);
   if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't open macro file for writting.");
+    QMessageBox::critical(this, "ERROR", "Couldn't open macro file for writting.");
     return;
   }
 
@@ -1869,7 +1869,7 @@ void PmuppGui::createMacro()
     xx = getValues(collName, xLabel, ok);
     if (!ok) {
       QString msg = QString("Couldn't get x-axis data from '%1', coll: '%2'").arg(xLabel).arg(collName);
-      QMessageBox::critical(this, "**ERROR**", msg);
+      QMessageBox::critical(this, "ERROR", msg);
       return;
     }
     getMinMax(xx, xMin, xMax);
@@ -1886,19 +1886,19 @@ void PmuppGui::createMacro()
       yy = getValues(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yyPosErr = getPosErr(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis pos. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yyNegErr = getNegErr(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis neg. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yLabel = substituteDefaultLabels(yLabel);
@@ -2015,7 +2015,7 @@ void PmuppGui::plot()
 {
   // check if there is something to be plotted
   if (fXY.size() == 0) {
-    QMessageBox::information(this, "plot", "No parameter list present.");
+    QMessageBox::information(this, "PLOT", "No parameter list present.");
     return;
   }
 
@@ -2058,7 +2058,7 @@ void PmuppGui::plot()
     xx = getValues(collName, xLabel, ok);
     if (!ok) {
       QString msg = QString("Couldn't get x-axis data from '%1', coll: '%2'").arg(xLabel).arg(collName);
-      QMessageBox::critical(this, "**ERROR**", msg);
+      QMessageBox::critical(this, "ERROR", msg);
       return;
     }
 
@@ -2073,21 +2073,21 @@ void PmuppGui::plot()
       yy = getValues(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yyy.push_back(yy);
       yyPosErr = getPosErr(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis pos. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yyyPosErr.push_back(yyPosErr);
       yyNegErr = getNegErr(collName, yLabel, ok);
       if (!ok) {
         QString msg = QString("Couldn't get y-axis neg. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-        QMessageBox::critical(this, "**ERROR**", msg);
+        QMessageBox::critical(this, "ERROR", msg);
         return;
       }
       yyyNegErr.push_back(yyNegErr);
@@ -2103,21 +2103,21 @@ void PmuppGui::plot()
     yy = getValues(collName, yLabel, ok);
     if (!ok) {
       QString msg = QString("Couldn't get y-axis data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-      QMessageBox::critical(this, "**ERROR**", msg);
+      QMessageBox::critical(this, "ERROR", msg);
       return;
     }
     yyy.push_back(yy);
     yyPosErr = getPosErr(collName, yLabel, ok);
     if (!ok) {
       QString msg = QString("Couldn't get y-axis pos. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-      QMessageBox::critical(this, "**ERROR**", msg);
+      QMessageBox::critical(this, "ERROR", msg);
       return;
     }
     yyyPosErr.push_back(yyPosErr);
     yyNegErr = getNegErr(collName, yLabel, ok);
     if (!ok) {
       QString msg = QString("Couldn't get y-axis neg. error data from '%1', coll: '%2'").arg(yLabel).arg(collName);
-      QMessageBox::critical(this, "**ERROR**", msg);
+      QMessageBox::critical(this, "ERROR", msg);
       return;
     }
     yyyNegErr.push_back(yyNegErr);
@@ -2237,7 +2237,7 @@ void PmuppGui::startMuppPlot()
 
   fMuppPlot = new QProcess(this);
   if (fMuppPlot == nullptr) {
-    QMessageBox::critical(0, "**ERROR**", "Couldn't invoke QProcess for mupp_plot!");
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke QProcess for mupp_plot!");
     return;
   }
 
@@ -2253,10 +2253,7 @@ void PmuppGui::startMuppPlot()
   if (!fMuppPlot->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd);
-    QMessageBox::critical( 0,
-                          tr("Fatal error"),
-                          msg,
-                          tr("Quit") );
+    QMessageBox::critical(this, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -2296,7 +2293,7 @@ void PmuppGui::handleCmds()
     fMacroName = tok[1];
     createMacro();
   } else if (cmd.startsWith("path")) { // cmd: path <macro_path>
-    QMessageBox::information(0, "INFO", "set's eventually the path for the macros to be saved.");
+    QMessageBox::information(this , "INFO", "set's eventually the path for the macros to be saved.");
     // will set the path to where to save the macro
     QStringList tok = cmd.split(" ", Qt::SkipEmptyParts);
     if (tok.size() != 2) {
@@ -2316,7 +2313,7 @@ void PmuppGui::handleCmds()
       QString fullPath = env.value(envVar); // get environment variable value if present, otherwise "" is returned
       if (fullPath.isEmpty()) {
         fMacroPath = "";
-        QMessageBox::critical(0, "ERROR", QString("Environment variable '%1' not present. Typo?!").arg(envVar.prepend("$")));
+        QMessageBox::critical(this, "ERROR", QString("Environment variable '%1' not present. Typo?!").arg(envVar.prepend("$")));
         return;
       }
       fMacroPath.replace(envVar.prepend("$"), fullPath);
@@ -2328,13 +2325,13 @@ void PmuppGui::handleCmds()
     if (tok.size() > 1)
       addX(tok[1]);
     else
-      QMessageBox::critical(0, "ERROR", QString("Found command 'x' without variable."));
+      QMessageBox::critical(this, "ERROR", QString("Found command 'x' without variable."));
   } else if (cmd.startsWith("y")) {
     QStringList tok = cmd.split(" ", Qt::SkipEmptyParts);
     if (tok.size() > 1)
       addY(tok[1]);
     else
-      QMessageBox::critical(0, "ERROR", QString("Found command 'y' without variable."));
+      QMessageBox::critical(this, "ERROR", QString("Found command 'y' without variable."));
   } else if (cmd.startsWith("ditto")) {
     addDitto();
   } else if (cmd.startsWith("rmx")) {
@@ -2342,17 +2339,17 @@ void PmuppGui::handleCmds()
     if (tok.size() > 1)
       removeX(tok[1]);
     else
-      QMessageBox::critical(0, "ERROR", QString("Found command 'rmx' without variable."));
+      QMessageBox::critical(this, "ERROR", QString("Found command 'rmx' without variable."));
   } else if (cmd.startsWith("rmy")) {
     QStringList tok = cmd.split(" ", Qt::SkipEmptyParts);
     if (tok.size() > 1)
       removeY(tok[1]);
     else
-      QMessageBox::critical(0, "ERROR", QString("Found command 'rmy' without variable."));
+      QMessageBox::critical(this, "ERROR", QString("Found command 'rmy' without variable."));
   } else if (cmd.startsWith("norm")) {
     QStringList tok = cmd.split(" ", Qt::SkipEmptyParts);
     if (tok.size() != 2) {
-      QMessageBox::critical(this, "**ERROR**", "found wrong norm cmd, will ignore it.");
+      QMessageBox::critical(this, "ERROR", "found wrong norm cmd, will ignore it.");
       return;
     }
     if (!tok[1].trimmed().compare("true", Qt::CaseInsensitive)) {
@@ -2360,7 +2357,7 @@ void PmuppGui::handleCmds()
     } else if (!tok[1].trimmed().compare("false", Qt::CaseInsensitive)) {
       fNormalizeAction->setChecked(false);
     } else {
-      QMessageBox::critical(this, "**ERROR**", "found wrong norm cmd, will ignore it.");
+      QMessageBox::critical(this, "ERROR", "found wrong norm cmd, will ignore it.");
       return;
     }
   } else if (cmd.startsWith("add var")) {
@@ -2626,7 +2623,7 @@ void PmuppGui::selectCollection(QString cmd)
     if (ival < fColList->count())
       fColList->setCurrentRow(ival);
     else
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
             QString("Found Row Selection %1 which is > #Selections=%2").arg(ival).arg(fColList->count()));
   } else { // assume it is a collection name
     for (int i=0; i<fColList->count(); i++) {
diff --git a/src/musredit_qt6/musrStep/PMusrStep.cpp b/src/musredit_qt6/musrStep/PMusrStep.cpp
index 92feba83..cef86072 100644
--- a/src/musredit_qt6/musrStep/PMusrStep.cpp
+++ b/src/musredit_qt6/musrStep/PMusrStep.cpp
@@ -167,7 +167,7 @@ PMusrStep::PMusrStep(const char *fln, QWidget *parent) :
     fValid = true;
   } else {
     QString msg = QString("Failed to read msr-file: %1 (status=%2)").arg(fMsrFileName).arg(status);
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(nullptr, "ERROR", msg);
   }
 
   int height;
@@ -261,7 +261,7 @@ void PMusrStep::handleCellChanged(int row, int column)
     if ((fParamTable->item(row, column)->checkState() == Qt::Checked) &&
         ((str == "0") || (str == "0.0"))) {
       fParamTable->item(row, column)->setCheckState(Qt::Unchecked);
-      QMessageBox::warning(0, "WARNING", "You cannot select a fixed value (step == 0).");
+      QMessageBox::warning(nullptr, "WARNING", "You cannot select a fixed value (step == 0).");
     }
   } else if (column == 2) {
     str = fParamTable->item(row, column)->text();
diff --git a/src/musredit_qt6/musrWiz/PAdmin.cpp b/src/musredit_qt6/musrWiz/PAdmin.cpp
index 2ccaadd1..58d46057 100644
--- a/src/musredit_qt6/musrWiz/PAdmin.cpp
+++ b/src/musredit_qt6/musrWiz/PAdmin.cpp
@@ -96,7 +96,7 @@ bool PFuncXMLParser::parse(QIODevice *device)
   if (fXml.hasError()) {
     QString msg;
     msg = QString("%1 Line %2, column %3").arg(fXml.errorString()).arg(fXml.lineNumber()).arg(fXml.columnNumber());
-    QMessageBox::critical(0, "**ERROR**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(nullptr, "ERROR", msg, QMessageBox::Ok, QMessageBox::NoButton);
     return false;
   }
 
@@ -140,7 +140,7 @@ bool PFuncXMLParser::startElement()
     QXmlStreamAttributes qAttr = fXml.attributes();
     if (qAttr.count() != 2) {
       errMsg = QString("theo_map should have 2 attributes, called 'no', and 'name', found %1").arg(qAttr.count());
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     PParam map;
@@ -149,7 +149,7 @@ bool PFuncXMLParser::startElement()
     ival = str.toInt(&ok);
     if (!ok) {
       errMsg = QString("theo_map attribute 'no' is not a number (%1)").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     map.setNumber(ival);
@@ -160,7 +160,7 @@ bool PFuncXMLParser::startElement()
     // check that all necessary attributes where found
     if ((map.getName() == "UnDef") || (map.getNumber() == -1)) {
       errMsg = QString("found theo_map with missing attribute(s)");
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     fTheoTemplate.appendMap(map);
@@ -168,7 +168,7 @@ bool PFuncXMLParser::startElement()
     QXmlStreamAttributes qAttr = fXml.attributes();
     if ((qAttr.count() != 4) && (qAttr.count() != 6)) {
       errMsg = QString("template_param should have 4 or 6 attributes, called\n'no', 'name', 'value', 'step', ['boundLow', 'boundHigh'] found %1").arg(qAttr.count());
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     PParam param;
@@ -177,7 +177,7 @@ bool PFuncXMLParser::startElement()
     ival = str.toInt(&ok);
     if (!ok) {
       errMsg = QString("template_param attribute 'no' is not a number (%1)").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     param.setNumber(ival);
@@ -189,7 +189,7 @@ bool PFuncXMLParser::startElement()
     dval = str.toDouble(&ok);
     if (!ok) {
       errMsg = QString("template_param attribute 'value' is not a number (%1)").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     param.setValue(dval);
@@ -198,7 +198,7 @@ bool PFuncXMLParser::startElement()
     dval = str.toDouble(&ok);
     if (!ok) {
       errMsg = QString("template_param attribute 'step' is not a number (%1)").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     param.setStep(dval);
@@ -378,7 +378,7 @@ bool PInstrumentDefXMLParser::parse(QIODevice *device)
   if (fXml.hasError()) {
     QString msg;
     msg = QString("%1 Line %2, column %3").arg(fXml.errorString()).arg(fXml.lineNumber()).arg(fXml.columnNumber());
-    QMessageBox::critical(0, "**ERROR**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(nullptr, "ERROR", msg, QMessageBox::Ok, QMessageBox::NoButton);
     return false;
   }
 
@@ -419,12 +419,12 @@ bool PInstrumentDefXMLParser::startElement()
     QXmlStreamAttributes qAttr = fXml.attributes();
     if (qAttr.count() != 1) {
       errMsg = QString("instrument should have 1 attribute, called 'name', found %1").arg(qAttr.count());
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     if (fInstituteName == "") {
       errMsg = QString("found instrument without institute set.");
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     // create an instrument object
@@ -633,13 +633,13 @@ bool PInstrumentDefXMLParser::characters()
   case eNoOfDetectors:
     if (fSetup == 0) {
       errMsg = "setup object not found.";
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     ival = str.toInt(&ok);
     if (!ok) {
       errMsg = QString("Setup Error: No of Detectors = '%1', which is not an int.").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     fSetup->setNoOfDetectors(ival);
@@ -664,7 +664,7 @@ bool PInstrumentDefXMLParser::characters()
     strList = str.split(' ', Qt::SkipEmptyParts);
     if (strList.size() != 2) {
       errMsg = QString("Found wrong Asymmetry background range: '%1'").arg(str);
-      QMessageBox::critical(0, "ERROR", errMsg);
+      QMessageBox::critical(nullptr, "ERROR", errMsg);
       return false;
     }
     start = strList[0].toInt(&ok);
@@ -692,7 +692,7 @@ bool PInstrumentDefXMLParser::characters()
 bool PInstrumentDefXMLParser::endDocument()
 {
   if (fInstituteName == "") {
-    QMessageBox::critical(0, "FATAL ERROR", "Didn't find any institute name in the instrument definitions.");
+    QMessageBox::critical(nullptr, "FATAL ERROR", "Didn't find any institute name in the instrument definitions.");
     return false;
   }
 
@@ -765,7 +765,7 @@ bool PMusrWizDefaultXMLParser::parse(QIODevice *device)
   if (fXml.hasError()) {
     QString msg;
     msg = QString("%1 Line %2, column %3").arg(fXml.errorString()).arg(fXml.lineNumber()).arg(fXml.columnNumber());
-    QMessageBox::critical(0, "**ERROR**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(nullptr, "ERROR", msg, QMessageBox::Ok, QMessageBox::NoButton);
     return false;
   }
 
@@ -876,7 +876,7 @@ PAdmin::PAdmin() : QObject()
     path = std::getenv("HOME");
     pathFln = path + "/.musrfit/musrWiz/musrWiz.xml";
     if (loadMusrWizDefault(pathFln)) {
-      QMessageBox::warning(0, "WARNING", "Couldn't find musrWiz.xml file.");
+      QMessageBox::warning(nullptr, "WARNING", "Couldn't find musrWiz.xml file.");
     }
   }
 
@@ -889,7 +889,7 @@ PAdmin::PAdmin() : QObject()
     pathFln = path + "/.musrfit/musrWiz/musrfit_funcs.xml";
     if (loadMusrfitFunc(pathFln)) {
       fValid = false;
-      QMessageBox::critical(0, "FATAL ERROR", "Couldn't find any musrfit function definitions.");
+      QMessageBox::critical(nullptr, "FATAL ERROR", "Couldn't find any musrfit function definitions.");
       return;
     }
   }
@@ -918,7 +918,7 @@ PAdmin::PAdmin() : QObject()
   }
 
   if (count == 0) {
-    QMessageBox::critical(0, "FATAL ERROR", "Couldn't find any instrument definition.");
+    QMessageBox::critical(nullptr, "FATAL ERROR", "Couldn't find any instrument definition.");
     fValid = false;
   }
 }
@@ -1215,7 +1215,7 @@ int PAdmin::loadMusrWizDefault(QString fln)
         cout << "**INFO** '" << pathName.toLatin1().data() << "' did not exist, hence it is created." << endl;
       } else {
         QString msg = QString("Couldn't create '%1'. Please check.").arg(pathName);
-        QMessageBox::critical(0, "ERROR", msg);
+        QMessageBox::critical(nullptr, "ERROR", msg);
         return 1;
       }
     }
@@ -1224,7 +1224,7 @@ int PAdmin::loadMusrWizDefault(QString fln)
   PMusrWizDefaultXMLParser handler(fln, this);
   if (!handler.isValid()) {
     QString errMsg = QString("Error parsing %1 file.").arg(fln);
-    QMessageBox::critical(0, "ERROR", errMsg);
+    QMessageBox::critical(nullptr, "ERROR", errMsg);
     return 1;
   }
   return 0;
@@ -1248,7 +1248,7 @@ int PAdmin::loadMusrfitFunc(QString fln)
         cout << "**INFO** '" << pathName.toLatin1().data() << "' did not exist, hence it is created." << endl;
       } else {
         QString msg = QString("Couldn't create '%1'. Please check.").arg(pathName);
-        QMessageBox::critical(0, "ERROR", msg);
+        QMessageBox::critical(nullptr, "ERROR", msg);
         return 1;
       }
     }
@@ -1257,7 +1257,7 @@ int PAdmin::loadMusrfitFunc(QString fln)
   PFuncXMLParser handler(fln, this);
   if (!handler.isValid()) {
     QString errMsg = QString("Error parsing %1 musrfit func file.").arg(fln);
-    QMessageBox::critical(0, "ERROR", errMsg);
+    QMessageBox::critical(nullptr, "ERROR", errMsg);
     return 1;
   }
   return 0;
@@ -1286,7 +1286,7 @@ int PAdmin::loadInstrumentDef(QString path, QString fln)
         cout << "**INFO** '" << pathName.toLatin1().data() << "' did not exist, hence it is created." << endl;
       } else {
         QString msg = QString("Couldn't create '%1'. Please check.").arg(pathName);
-        QMessageBox::critical(0, "ERROR", msg);
+        QMessageBox::critical(nullptr, "ERROR", msg);
         return 1;
       }
     } else {
@@ -1297,7 +1297,7 @@ int PAdmin::loadInstrumentDef(QString path, QString fln)
   PInstrumentDefXMLParser handler(pathFln, this);
   if (!handler.isValid()) {
     QString errMsg = QString("Error parsing %1 instrument def file.").arg(pathFln);
-    QMessageBox::critical(0, "ERROR", errMsg);
+    QMessageBox::critical(nullptr, "ERROR", errMsg);
     return 1;
   }
 
diff --git a/src/musredit_qt6/musrWiz/PMusrWiz.cpp b/src/musredit_qt6/musrWiz/PMusrWiz.cpp
index 86ac10c0..88b41599 100644
--- a/src/musredit_qt6/musrWiz/PMusrWiz.cpp
+++ b/src/musredit_qt6/musrWiz/PMusrWiz.cpp
@@ -553,7 +553,7 @@ void PIntroPage::handleFitType(int idx)
 {
   if ( (idx != FIT_TYPE_SINGLE_HISTO) &&
        (idx != FIT_TYPE_ASYMMETRY) ){
-    QMessageBox::warning(0, "WARNING", "Currently only fit type: single histo and asymmetry available.");
+    QMessageBox::warning(this, "WARNING", "Currently only fit type: single histo and asymmetry available.");
     fFitType->setCurrentIndex(FIT_TYPE_SINGLE_HISTO);
   }
 }
@@ -580,7 +580,7 @@ void PIntroPage::checkSetup(int idx)
   case MEASURE_LF:
     setup = instru->getLFSetups();
     measure = "LF";
-    QMessageBox::information(0, "INFO", "Not yet implemented.");
+    QMessageBox::information(this, "INFO", "Not yet implemented.");
     break;
   case MEASURE_UNDEF:
   default:
@@ -589,7 +589,7 @@ void PIntroPage::checkSetup(int idx)
 
   if (setup.size() == 0) {
     QString msg = QString("Didn't find any setup for:\nInstitute: %1\nInstrument: %2").arg(fInstitute->currentText()).arg(fInstrument->currentText());
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(this, "ERROR", msg);
     return;
   } else if (setup.size() == 1) {
     if (setup[0].getName() == "Default") {
@@ -907,7 +907,7 @@ void PTheoPage::checkTheory()
       ok = analyzeTokens(line[i], 0);
       if (!ok) {
         QString str = QString("**ERROR** in line %1.\n funX takes no parameter.").arg(i+1);
-        QMessageBox::critical(0, "Check Theory", str);
+        QMessageBox::critical(this, "Check Theory", str);
         // eventually it would be nice to highlight the faulty line
         return;
       }
@@ -915,7 +915,7 @@ void PTheoPage::checkTheory()
         ok = analyzeTokens(line[i], 0);
         if (!ok) {
           QString str = QString("**ERROR** in line %1.\n mapX takes no parameter.").arg(i+1);
-          QMessageBox::critical(0, "Check Theory", str);
+          QMessageBox::critical(this, "Check Theory", str);
           // eventually it would be nice to highlight the faulty line
           return;
         }
@@ -924,14 +924,14 @@ void PTheoPage::checkTheory()
       func = fAdmin->getMusrfitFunc(strList[0]);
       if (func.getName() == "UnDef") { // function not found
         QString str = QString("**ERROR** in line %1, '%2' is not a recognized musrfit function.").arg(i+1).arg(line[i]);
-        QMessageBox::critical(0, "Check Theory", str);
+        QMessageBox::critical(this, "Check Theory", str);
         // eventually it would be nice to highlight the faulty line
         return;
       }
       ok = analyzeTokens(line[i], func.getNoOfParam());
       if (!ok) {
         QString str = QString("**ERROR** in line %1.\n %2 takes %3 parameter.").arg(i+1).arg(func.getName()).arg(func.getNoOfParam());
-        QMessageBox::critical(0, "Check Theory", str);
+        QMessageBox::critical(this, "Check Theory", str);
         // eventually it would be nice to highlight the faulty line
         return;
       }
@@ -952,7 +952,7 @@ void PTheoPage::checkTheory()
 
   QObject *obj = sender();
   if (obj == fCheckTheo)
-    QMessageBox::information(0, "Check Theory", "Theory seems to be OK.");
+    QMessageBox::information(this, "Check Theory", "Theory seems to be OK.");
 }
 
 //-------------------------------------------------------------------------
@@ -1013,7 +1013,7 @@ bool PTheoPage::analyzeTokens(QString str, int noOfTokens)
         dealWithMap(tok[0], stokNo, 0);
       } else {
         QString msg = QString("Found map of the form '%1'.\nThis is NOT a legal map!").arg(tok[0]);
-        QMessageBox::critical(0, "analyzeTokens", msg);
+        QMessageBox::critical(this, "analyzeTokens", msg);
         return false;
       }
     } else if (tok[0].startsWith("fun")) {
@@ -1024,7 +1024,7 @@ bool PTheoPage::analyzeTokens(QString str, int noOfTokens)
         dealWithFun(stokNo);
       } else {
         QString msg = QString("Found fun of the form '%1'.\nThis is NOT a legal function!").arg(tok[0]);
-        QMessageBox::critical(0, "analyzeTokens", msg);
+        QMessageBox::critical(this, "analyzeTokens", msg);
         return false;
       }
     }
@@ -1043,7 +1043,7 @@ bool PTheoPage::analyzeTokens(QString str, int noOfTokens)
       dealWithParam(tok[0], paramNo, i);
     } else if (!tok[i].startsWith("map") && !tok[i].startsWith("fun")) {
       QString msg = QString("Found parameter of the form '%1'.\nThis is NOT a legal parameter!").arg(tok[i]);
-      QMessageBox::critical(0, "analyzeTokens", msg);
+      QMessageBox::critical(this, "analyzeTokens", msg);
       return false;
     }
   }
@@ -1060,7 +1060,7 @@ bool PTheoPage::analyzeTokens(QString str, int noOfTokens)
         dealWithMap(tok[0], mapNo, i);
       } else {
         QString msg = QString("Found map of the form '%1'.\nThis is NOT a legal map!").arg(tok[i]);
-        QMessageBox::critical(0, "analyzeTokens", msg);
+        QMessageBox::critical(this, "analyzeTokens", msg);
         return false;
       }
     }
@@ -1078,7 +1078,7 @@ bool PTheoPage::analyzeTokens(QString str, int noOfTokens)
         dealWithFun(funNo);
       } else {
         QString msg = QString("Found function of the form '%1'.\nThis is NOT a legal function!").arg(tok[i]);
-        QMessageBox::critical(0, "analyzeTokens", msg);
+        QMessageBox::critical(this, "analyzeTokens", msg);
         return false;
       }
     }
@@ -2015,7 +2015,7 @@ int PMusrWiz::writeMsrFile(int result)
   // no msr-file name given, hence generate it
   if (fMsrData->getMsrFileName() == QString("")) {
     if (fMsrData->getRunNumber() == -1) {
-      QMessageBox::critical(0, "ERROR", "No run number given! Won't do anything.");
+      QMessageBox::critical(this, "ERROR", "No run number given! Won't do anything.");
       return -2;
     }
     fMsrData->setMsrFileName(QString("%1").arg(fMsrData->getRunNumber()));
@@ -2062,7 +2062,7 @@ int PMusrWiz::writeMsrFileSingleHisto()
   QFile fln(pathFileName);
 
   if (!fln.open(QIODevice::WriteOnly | QIODevice::Text)) {
-    QMessageBox::critical(0, "ERROR", "Cannot open file for writting.");
+    QMessageBox::critical(this, "ERROR", "Cannot open file for writting.");
     return -3;
   }
 
@@ -2104,7 +2104,7 @@ int PMusrWiz::writeMsrFileSingleHisto()
   PInstrument *instru = fAdmin->getInstrument(fMsrData->getInstitute(), fMsrData->getInstrument());
   if (instru == 0) {
     QString msg = QString("No setups found for %1: %2").arg(fMsrData->getInstitute(), fMsrData->getInstrument());
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(this, "ERROR", msg);
     return -4;
   }
   PSetup *setup = 0;
@@ -2124,7 +2124,7 @@ int PMusrWiz::writeMsrFileSingleHisto()
   }
   if (setup == 0) {
     QString msg = QString("No setups found for %1: %2: %3").arg(fMsrData->getInstitute(), fMsrData->getInstrument()).arg(fMsrData->getSetup());
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(this, "ERROR", msg);
     return -5;
   }
   int noOfDetec = setup->getNoOfLogicalDetectors();
@@ -2295,7 +2295,7 @@ int PMusrWiz::writeMsrFileAsymmetry()
   QFile fln(pathFileName);
 
   if (!fln.open(QIODevice::WriteOnly | QIODevice::Text)) {
-    QMessageBox::critical(0, "ERROR", "Cannot open file for writting.");
+    QMessageBox::critical(this, "ERROR", "Cannot open file for writting.");
     return -3;
   }
 
@@ -2337,7 +2337,7 @@ int PMusrWiz::writeMsrFileAsymmetry()
   PInstrument *instru = fAdmin->getInstrument(fMsrData->getInstitute(), fMsrData->getInstrument());
   if (instru == 0) {
     QString msg = QString("No setups found for %1: %2").arg(fMsrData->getInstitute(), fMsrData->getInstrument());
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(this, "ERROR", msg);
     return -4;
   }
   PSetup *setup = 0;
@@ -2357,7 +2357,7 @@ int PMusrWiz::writeMsrFileAsymmetry()
   }
   if (setup == 0) {
     QString msg = QString("No setups found for %1: %2: %3").arg(fMsrData->getInstitute(), fMsrData->getInstrument()).arg(fMsrData->getSetup());
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(this, "ERROR", msg);
     return -5;
   }
   int noOfDetec = setup->getNoOfLogicalAsymDetectors();
@@ -2579,5 +2579,5 @@ QString PMusrWiz::getRunName(PInstrument *instru)
  */
 void PMusrWiz::help()
 {
-  QMessageBox::information(0, "Help", "Eventually there will be a help here.");
+  QMessageBox::information(this, "Help", "Eventually there will be a help here.");
 }
diff --git a/src/musredit_qt6/musrWiz/musrWiz.cpp b/src/musredit_qt6/musrWiz/musrWiz.cpp
index a886ac8c..273118ec 100644
--- a/src/musredit_qt6/musrWiz/musrWiz.cpp
+++ b/src/musredit_qt6/musrWiz/musrWiz.cpp
@@ -132,7 +132,7 @@ int main(int argc, char *argv[])
           arguments << pathFln;
           QProcess::startDetached(musrt0, arguments, "./");
         } else {
-          QMessageBox::warning(0, "WARNING", "Couldn't find musrt0 :-(.\n Only the msr-file has been generated.");
+          QMessageBox::warning(nullptr, "WARNING", "Couldn't find musrt0 :-(.\n Only the msr-file has been generated.");
         }
       }
     }
diff --git a/src/musredit_qt6/musredit/PAdmin.cpp b/src/musredit_qt6/musredit/PAdmin.cpp
index cbc1e433..742f4593 100644
--- a/src/musredit_qt6/musredit/PAdmin.cpp
+++ b/src/musredit_qt6/musredit/PAdmin.cpp
@@ -100,7 +100,7 @@ bool PAdminXMLParser::parse(QIODevice *device)
   if (fXml.hasError()) {
     QString msg;
     msg = QString("%1 Line %2, column %3").arg(fXml.errorString()).arg(fXml.lineNumber()).arg(fXml.columnNumber());
-    QMessageBox::critical(0, "**ERROR**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(nullptr, "ERROR", msg, QMessageBox::Ok, QMessageBox::NoButton);
     return false;
   }
 
@@ -699,14 +699,14 @@ QString PAdminXMLParser::expandPath(const QString &str)
       token.remove('$');
       if (!procEnv.contains(token)) {
         msg = QString("Couldn't find '%1'. Some things might not work properly").arg(token);
-        QMessageBox::warning(0, "**WARNING**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+        QMessageBox::warning(nullptr, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
         newStr = "";
         break;
       }
       path = procEnv.value(token, "");
       if (path.isEmpty()) {
         msg = QString("Couldn't expand '%1'. Some things might not work properly").arg(token);
-        QMessageBox::warning(0, "**WARNING**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+        QMessageBox::warning(nullptr, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
         newStr = "";
         break;
       }
@@ -807,9 +807,9 @@ PAdmin::PAdmin() : QObject()
   QFileInfo info(str);
   if (info.exists()) {
     if (!info.isExecutable())
-      QMessageBox::critical(0, "ERROR", "musrfit found but not recognized as executable.\nPlease check!");
+      QMessageBox::critical(nullptr, "ERROR", "musrfit found but not recognized as executable.\nPlease check!");
   } else {
-    QMessageBox::critical(0, "ERROR", "musrfit not found.\nHave you set the necessary system variables properly?\nPlease check the manual.\nBefore you can use musrfit, this needs to be fixed.");
+    QMessageBox::critical(nullptr, "ERROR", "musrfit not found.\nHave you set the necessary system variables properly?\nPlease check the manual.\nBefore you can use musrfit, this needs to be fixed.");
   }
 
   // check if system variables are set properly
@@ -827,7 +827,7 @@ PAdmin::PAdmin() : QObject()
   }
   if (sysVarMissing) {
     msg += "Please set this/these system variables.";
-    QMessageBox::warning(0, "WARNING", msg);
+    QMessageBox::warning(nullptr, "WARNING", msg);
   }
 }
 
@@ -907,13 +907,13 @@ int PAdmin::loadPrefs(QString fln)
   if (QFile::exists(fln)) { // administration file present
     PAdminXMLParser handler(fln, this);
     if (!handler.isValid()) {
-      QMessageBox::critical(0, "**ERROR**",
+      QMessageBox::critical(nullptr, "ERROR",
                             "Error parsing musredit_startup.xml settings file.\nProbably a few things will not work porperly.\nPlease fix this first.",
                             QMessageBox::Ok, QMessageBox::NoButton);
       return 0;
     }
   } else {
-    QMessageBox::critical(0, "**ERROR**",
+    QMessageBox::critical(nullptr, "ERROR",
                           "Couldn't find the musredit_startup.xml settings file.\nProbably a few things will not work porperly.\nPlease fix this first.",
                           QMessageBox::Ok, QMessageBox::NoButton);
     return 0;
@@ -1042,7 +1042,7 @@ int PAdmin::savePrefs(QString pref_fln)
     file.close();
   } else {
     QString msg("Failed to write musredit_startup.xml. Neither a local nor a global copy found.");
-    QMessageBox::warning(0, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::warning(nullptr, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
   }
 
   return 1;
@@ -1132,7 +1132,7 @@ void PAdmin::saveRecentFiles()
     file.close();
   } else {
     QString msg("Failed to write musredit_startup.xml. Neither a local nor a global copy found.");
-    QMessageBox::warning(0, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::warning(nullptr, "WARNING", msg, QMessageBox::Ok, QMessageBox::NoButton);
   }
 }
 
@@ -1161,13 +1161,13 @@ void PAdmin::createMusreditStartupFile()
   QFile fres(":/musredit_startup.xml.in");
   if (!fres.exists()) {
     QString msg = QString("Neither couldn't find nor create musredit_startup.xml. Things are likely not to work.");
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(nullptr, "ERROR", msg);
     return;
   }
 
   if (!fres.open(QIODevice::ReadOnly | QIODevice::Text)) {
     QString msg = QString("Couldn't open internal resource file musredit_startup.xml.in. Things are likely not to work.");
-    QMessageBox::critical(0, "ERROR", msg);
+    QMessageBox::critical(nullptr, "ERROR", msg);
     return;
   }
   // text stream for fres
diff --git a/src/musredit_qt6/musredit/PChangeDefaultPathsDialog.cpp b/src/musredit_qt6/musredit/PChangeDefaultPathsDialog.cpp
index 0ab70a12..f2e88439 100644
--- a/src/musredit_qt6/musredit/PChangeDefaultPathsDialog.cpp
+++ b/src/musredit_qt6/musredit/PChangeDefaultPathsDialog.cpp
@@ -92,7 +92,7 @@ bool PDefaultPathsXMLParser::parse(QIODevice *device)
   if (fXml.hasError()) {
     QString msg;
     msg = QString("%1 Line %2, column %3").arg(fXml.errorString()).arg(fXml.lineNumber()).arg(fXml.columnNumber());
-    QMessageBox::critical(0, "**ERROR**", msg, QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(nullptr, "ERROR", msg, QMessageBox::Ok, QMessageBox::NoButton);
     return false;
   }
 
@@ -204,7 +204,7 @@ PDefaultPaths::PDefaultPaths() : QObject()
   PDefaultPathsXMLParser handler(fPrefPathName, this);
   if (!handler.isValid()) {
     fValid = false;
-    QMessageBox::critical(0, "ERROR",
+    QMessageBox::critical(nullptr, "ERROR",
                           "Error parsing musrfit_startup.xml settings file.\nProbably a few things will not work porperly.\nPlease fix this first.",
                           QMessageBox::Ok, QMessageBox::NoButton);
     return;
diff --git a/src/musredit_qt6/musredit/PDumpOutputHandler.cpp b/src/musredit_qt6/musredit/PDumpOutputHandler.cpp
index 98598849..0d401fcd 100644
--- a/src/musredit_qt6/musredit/PDumpOutputHandler.cpp
+++ b/src/musredit_qt6/musredit/PDumpOutputHandler.cpp
@@ -83,10 +83,7 @@ PDumpOutputHandler::PDumpOutputHandler(QVector<QString> &cmd)
   if ( !fProc->waitForStarted() ) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( 0,
-                tr("Fatal error"),
-                msg,
-                tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     done(0);
   }
 
diff --git a/src/musredit_qt6/musredit/PFitOutputHandler.cpp b/src/musredit_qt6/musredit/PFitOutputHandler.cpp
index 553e8175..05c0a922 100644
--- a/src/musredit_qt6/musredit/PFitOutputHandler.cpp
+++ b/src/musredit_qt6/musredit/PFitOutputHandler.cpp
@@ -87,10 +87,7 @@ PFitOutputHandler::PFitOutputHandler(QString workingDirectory, QVector<QString>
   if ( !fProc->waitForStarted() ) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( nullptr,
-                tr("Fatal error"),
-                msg,
-                tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     done(0);
   }
   fProcPID = fProc->processId();
diff --git a/src/musredit_qt6/musredit/PGetAsymmetryRunBlockDialog.cpp b/src/musredit_qt6/musredit/PGetAsymmetryRunBlockDialog.cpp
index 89f13862..802782f9 100644
--- a/src/musredit_qt6/musredit/PGetAsymmetryRunBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetAsymmetryRunBlockDialog.cpp
@@ -282,15 +282,12 @@ QString PGetAsymmetryRunBlockDialog::getPacking(bool &present)
 void PGetAsymmetryRunBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetFourierBlockDialog.cpp b/src/musredit_qt6/musredit/PGetFourierBlockDialog.cpp
index cbb41b41..4d403bdc 100644
--- a/src/musredit_qt6/musredit/PGetFourierBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetFourierBlockDialog.cpp
@@ -82,14 +82,14 @@ void PGetFourierBlockDialog::checkPhaseParameter()
       ival = str.toInt(&ok);
       if (!ok) {
         fPhase_lineEdit->clear();
-        QMessageBox::critical(this, "**ERROR**",
+        QMessageBox::critical(this, "ERROR",
                               "Allowed phase entries are either a parameter number,\n or an parXX entry, where XX is a parameter number",
                               QMessageBox::Ok, QMessageBox::NoButton);
         fPhase_lineEdit->setFocus();
       }
     } else { // neither a parXX nor a number
       fPhase_lineEdit->clear();
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
                             "Allowed phase entries are either a parameter number,\n or an parXX entry, where XX is a parameter number",
                             QMessageBox::Ok, QMessageBox::NoButton);
         fPhase_lineEdit->setFocus();
@@ -130,15 +130,12 @@ void PGetFourierBlockDialog::fillFourierBlock()
 void PGetFourierBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetFunctionsBlockDialog.cpp b/src/musredit_qt6/musredit/PGetFunctionsBlockDialog.cpp
index 77c388fc..8d3b0b7d 100644
--- a/src/musredit_qt6/musredit/PGetFunctionsBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetFunctionsBlockDialog.cpp
@@ -106,15 +106,12 @@ void PGetFunctionsBlockDialog::addFunction()
 void PGetFunctionsBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetMusrFTOptionsDialog.cpp b/src/musredit_qt6/musredit/PGetMusrFTOptionsDialog.cpp
index 9636159e..43e81f6d 100644
--- a/src/musredit_qt6/musredit/PGetMusrFTOptionsDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetMusrFTOptionsDialog.cpp
@@ -585,15 +585,12 @@ void PGetMusrFTOptionsDialog::averagedPerDataSet(int state)
 void PGetMusrFTOptionsDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetNonMusrRunBlockDialog.cpp b/src/musredit_qt6/musredit/PGetNonMusrRunBlockDialog.cpp
index 1b16318e..225aac7f 100644
--- a/src/musredit_qt6/musredit/PGetNonMusrRunBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetNonMusrRunBlockDialog.cpp
@@ -155,15 +155,12 @@ QString PGetNonMusrRunBlockDialog::getFitRange(bool &valid)
 void PGetNonMusrRunBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetParameterBlockDialog.cpp b/src/musredit_qt6/musredit/PGetParameterBlockDialog.cpp
index 26b5edab..f4f8937a 100644
--- a/src/musredit_qt6/musredit/PGetParameterBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetParameterBlockDialog.cpp
@@ -105,7 +105,7 @@ void PGetParameterBlockDialog::paramAdd()
   // get name
   str = fName_lineEdit->text();
   if (str.isEmpty()) {
-    QMessageBox::critical(this, "**ERROR**",
+    QMessageBox::critical(this, "ERROR",
        "empty parameter name not allowed!",
        QMessageBox::Ok, QMessageBox::NoButton);
     return;
@@ -120,7 +120,7 @@ void PGetParameterBlockDialog::paramAdd()
   // get value
   str = fValue_lineEdit->text();
   if (str.isEmpty()) {
-    QMessageBox::critical(this, "**ERROR**",
+    QMessageBox::critical(this, "ERROR",
        "empty parameter value not allowed!",
        QMessageBox::Ok, QMessageBox::NoButton);
     return;
@@ -135,7 +135,7 @@ void PGetParameterBlockDialog::paramAdd()
   // get step
   str = fStep_lineEdit->text();
   if (str.isEmpty()) {
-    QMessageBox::critical(this, "**ERROR**",
+    QMessageBox::critical(this, "ERROR",
        "empty parameter step not allowed!",
        QMessageBox::Ok, QMessageBox::NoButton);
     return;
@@ -156,7 +156,7 @@ void PGetParameterBlockDialog::paramAdd()
     bool ok;
     double val = str.toDouble(&ok);
     if (!ok && (str != "none")) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "invalid lower boundary! Must be a double are the key word 'none'",
          QMessageBox::Ok, QMessageBox::NoButton);
       return;
@@ -172,7 +172,7 @@ void PGetParameterBlockDialog::paramAdd()
     str = fUpper_lineEdit->text();
     val = str.toDouble(&ok);
     if (!ok && (str != "none")) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "invalid upper boundary! Must be a double are the key word 'none'",
          QMessageBox::Ok, QMessageBox::NoButton);
       return;
@@ -218,15 +218,12 @@ void PGetParameterBlockDialog::paramAdd()
 void PGetParameterBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetPlotBlockDialog.cpp b/src/musredit_qt6/musredit/PGetPlotBlockDialog.cpp
index bf034d81..86a19200 100644
--- a/src/musredit_qt6/musredit/PGetPlotBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetPlotBlockDialog.cpp
@@ -97,7 +97,7 @@ void PGetPlotBlockDialog::addPlot()
   // lower x-/time range
   str = fXRangeLow_lineEdit->text();
   if (str.isEmpty()) {
-    QMessageBox::critical(this, "**ERROR**",
+    QMessageBox::critical(this, "ERROR",
        "empty lower time-/x-range name not allowed!",
        QMessageBox::Ok, QMessageBox::NoButton);
     return;
@@ -111,7 +111,7 @@ void PGetPlotBlockDialog::addPlot()
   // upper x-/time range
   str = fXRangeUp_lineEdit->text();
   if (str.isEmpty()) {
-    QMessageBox::critical(this, "**ERROR**",
+    QMessageBox::critical(this, "ERROR",
        "empty upper time-/x-range name not allowed!",
        QMessageBox::Ok, QMessageBox::NoButton);
     return;
@@ -125,7 +125,7 @@ void PGetPlotBlockDialog::addPlot()
   // check y-range: either none given or both
   if ((fYRangeLow_lineEdit->text().isEmpty() && !fYRangeUp_lineEdit->text().isEmpty()) ||
       (!fYRangeLow_lineEdit->text().isEmpty() && fYRangeUp_lineEdit->text().isEmpty())) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Only fully empty y-range, or give lower AND upper y-range is acceptable!\n Will ignore the y-range",
          QMessageBox::Ok, QMessageBox::NoButton);
   } else if (!fYRangeLow_lineEdit->text().isEmpty() && !fYRangeUp_lineEdit->text().isEmpty()) {
@@ -159,15 +159,12 @@ void PGetPlotBlockDialog::addPlot()
 void PGetPlotBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetSingleHistoRunBlockDialog.cpp b/src/musredit_qt6/musredit/PGetSingleHistoRunBlockDialog.cpp
index 4db935d7..415a2e0c 100644
--- a/src/musredit_qt6/musredit/PGetSingleHistoRunBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetSingleHistoRunBlockDialog.cpp
@@ -281,15 +281,12 @@ QString PGetSingleHistoRunBlockDialog::getLifetimeCorrection(bool &present)
 void PGetSingleHistoRunBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetTheoryBlockDialog.cpp b/src/musredit_qt6/musredit/PGetTheoryBlockDialog.cpp
index e559ec1e..205ee5ec 100644
--- a/src/musredit_qt6/musredit/PGetTheoryBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetTheoryBlockDialog.cpp
@@ -125,15 +125,12 @@ void PGetTheoryBlockDialog::addMultiply()
 void PGetTheoryBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PGetTitleBlockDialog.cpp b/src/musredit_qt6/musredit/PGetTitleBlockDialog.cpp
index 459ed9dc..68a8bc20 100644
--- a/src/musredit_qt6/musredit/PGetTitleBlockDialog.cpp
+++ b/src/musredit_qt6/musredit/PGetTitleBlockDialog.cpp
@@ -53,15 +53,12 @@ PGetTitleBlockDialog::PGetTitleBlockDialog(const QString helpUrl) : fHelpUrl(hel
 void PGetTitleBlockDialog::helpContent()
 {
   if (fHelpUrl.isEmpty()) {
-    QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+    QMessageBox::information(this, "INFO", "Will eventually show a help window");
   } else {
     bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
     if (!ok) {
       QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal Error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     }
   }
 }
diff --git a/src/musredit_qt6/musredit/PMsr2DataDialog.cpp b/src/musredit_qt6/musredit/PMsr2DataDialog.cpp
index 0d8054dc..c1434639 100644
--- a/src/musredit_qt6/musredit/PMsr2DataDialog.cpp
+++ b/src/musredit_qt6/musredit/PMsr2DataDialog.cpp
@@ -222,15 +222,12 @@ void PMsr2DataDialog::fitOnlyChanged(int buttonState)
 void PMsr2DataDialog::helpContent()
 {
     if (fHelpUrl.isEmpty()) {
-      QMessageBox::information(this, "**INFO**", "Will eventually show a help window");
+      QMessageBox::information(this, "INFO", "Will eventually show a help window");
     } else {
       bool ok = QDesktopServices::openUrl(QUrl(fHelpUrl, QUrl::TolerantMode));
       if (!ok) {
         QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fHelpUrl);
-        QMessageBox::critical( nullptr,
-                               tr("Fatal Error"),
-                               msg,
-                               tr("Quit") );
+        QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
       }
     }
 }
diff --git a/src/musredit_qt6/musredit/PSubTextEdit.cpp b/src/musredit_qt6/musredit/PSubTextEdit.cpp
index 0209dae4..0e57089f 100644
--- a/src/musredit_qt6/musredit/PSubTextEdit.cpp
+++ b/src/musredit_qt6/musredit/PSubTextEdit.cpp
@@ -252,7 +252,7 @@ void PSubTextEdit::insertAsymRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Given map not valid, will add a default map line",
          QMessageBox::Ok, QMessageBox::NoButton);
       str += "map             0  0  0  0  0  0  0  0  0  0\n";
@@ -268,7 +268,7 @@ void PSubTextEdit::insertAsymRunBlock()
     workStr = dlg->getBackground(valid);
     str += workStr;
     if (!valid) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Either <b>background</b> or <b>backgr.fix</b> is needed!\nWill set <b>background</b> to 0..10, please correct!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -278,7 +278,7 @@ void PSubTextEdit::insertAsymRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Not all Data entries are present.Fix is needed!\nWill not set anything!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -288,7 +288,7 @@ void PSubTextEdit::insertAsymRunBlock()
     if (present) {
       str += workStr;
     } else {
-      QMessageBox::warning(this, "**ERROR**",
+      QMessageBox::warning(this, "ERROR",
          "T0's not given, assume that they are present in the data file!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -297,7 +297,7 @@ void PSubTextEdit::insertAsymRunBlock()
     workStr = dlg->getFitRange(valid);
     str += workStr;
     if (!valid) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "No valid fit range is given.Fix is needed!\nWill add a default one!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -306,7 +306,7 @@ void PSubTextEdit::insertAsymRunBlock()
     workStr = dlg->getPacking(present);
     str += workStr;
     if (!present) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "No valid packing/binning is given.Fix is needed!\nWill add a default one!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -347,7 +347,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Given map not valid, will add a default map line",
          QMessageBox::Ok, QMessageBox::NoButton);
       str += "map             0  0  0  0  0  0  0  0  0  0\n";
@@ -375,7 +375,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     workStr = dlg->getBackground(valid);
     str += workStr;
     if (!valid) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Either <b>background</b>, <b>backgr.fix</b>, or <b>backgr.fit</b> is needed!\nWill set <b>background</b> to 0..10, please correct!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -385,7 +385,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     if (present) {
       str += workStr;
     } else {
-      QMessageBox::warning(this, "**ERROR**",
+      QMessageBox::warning(this, "ERROR",
          "T0's not given, assume that they are present in the data file!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -395,7 +395,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Not all Data entries are present.Fix is needed!\nWill not set anything!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -404,7 +404,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     workStr = dlg->getFitRange(valid);
     str += workStr;
     if (!valid) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "No valid fit range is given.Fix is needed!\nWill add a default one!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -413,7 +413,7 @@ void PSubTextEdit::insertSingleHistRunBlock()
     workStr = dlg->getPacking(present);
     str += workStr;
     if (!present) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "No valid packing/binning is given.Fix is needed!\nWill add a default one!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -453,7 +453,7 @@ void PSubTextEdit::insertNonMusrRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Given map not valid, will add a default map line",
          QMessageBox::Ok, QMessageBox::NoButton);
       str += "map             0  0  0  0  0  0  0  0  0  0\n";
@@ -464,7 +464,7 @@ void PSubTextEdit::insertNonMusrRunBlock()
     if (valid) {
       str += workStr;
     } else {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "Not all xy-data entries are present.Fix is needed!\nWill not set anything!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
@@ -473,7 +473,7 @@ void PSubTextEdit::insertNonMusrRunBlock()
     workStr = dlg->getFitRange(valid);
     str += workStr;
     if (!valid) {
-      QMessageBox::critical(this, "**ERROR**",
+      QMessageBox::critical(this, "ERROR",
          "No valid fit range is given.Fix is needed!\nWill add a default one!",
          QMessageBox::Ok, QMessageBox::NoButton);
     }
diff --git a/src/musredit_qt6/musredit/PTextEdit.cpp b/src/musredit_qt6/musredit/PTextEdit.cpp
index 4f280afe..b45b0867 100644
--- a/src/musredit_qt6/musredit/PTextEdit.cpp
+++ b/src/musredit_qt6/musredit/PTextEdit.cpp
@@ -110,7 +110,7 @@ PTextEdit::PTextEdit( QWidget *parent )
   fFileSystemWatcherActive = true;
   fFileSystemWatcher = new QFileSystemWatcher();
   if (fFileSystemWatcher == nullptr) {
-    QMessageBox::information(this, "**ERROR**", "Couldn't invoke QFileSystemWatcher!");
+    QMessageBox::information(this, "ERROR", "Couldn't invoke QFileSystemWatcher!");
   } else {
     connect( fFileSystemWatcher, SIGNAL(fileChanged(const QString&)), this, SLOT(fileChanged(const QString&)));
   }
@@ -1280,7 +1280,7 @@ void PTextEdit::fileOpenRecent()
 void PTextEdit::fileReload()
 {
   if ( fFilenames.find( currentEditor() ) == fFilenames.end() ) {
-    QMessageBox::critical(this, "**ERROR**", "Cannot reload a file not previously saved ;-)");
+    QMessageBox::critical(this, "ERROR", "Cannot reload a file not previously saved ;-)");
   } else {
     int index = fTabWidget->currentIndex();
     QString fln = *fFilenames.find( currentEditor() );
@@ -1308,7 +1308,7 @@ void PTextEdit::fileOpenPrefs()
   } else if (result == 0) { // default dir
     fln = fAdmin->getDefaultPrefPathName();
     msg = QString("Current Default Preferences Path-Name:\n") + fln;
-    if (QMessageBox::information(this, "Info", msg, QMessageBox::Ok, QMessageBox::Cancel) == QMessageBox::Cancel)
+    if (QMessageBox::information(this, "INFO", msg, QMessageBox::Ok, QMessageBox::Cancel) == QMessageBox::Cancel)
       return;
   } else if (result == 1) { // custom dir
     fln = QFileDialog::getOpenFileName( this, tr("Open Prefs"),
@@ -1318,7 +1318,7 @@ void PTextEdit::fileOpenPrefs()
 
   if (fAdmin->loadPrefs(fln)) {
     msg = QString("Prefs from '") + fln + QString("' loaded.");
-    QMessageBox::information(nullptr, "Info", msg);
+    QMessageBox::information(nullptr, "INFO", msg);
   }
 
   // make sure that dark/plain icon scheme is properly loaded
@@ -1354,7 +1354,7 @@ void PTextEdit::fileSave()
   } else {
     QFile file( *fFilenames.find( currentEditor() ) );
     if ( !file.open( QIODevice::WriteOnly ) ) {
-      QMessageBox::critical(this, "**ERROR**", "Couldn't save the file!\nDisk full?\nNo write access?");
+      QMessageBox::critical(this, "ERROR", "Couldn't save the file!\nDisk full?\nNo write access?");
       return;
     }
     QTextStream ts( &file );
@@ -1411,7 +1411,7 @@ void PTextEdit::fileSavePrefs()
   } else if (result == 0) { // default dir
     fln = fAdmin->getDefaultPrefPathName();
     msg = QString("Current Default Preferences Path-Name:\n") + fln;
-    if (QMessageBox::information(this, "Info", msg, QMessageBox::Ok, QMessageBox::Cancel) == QMessageBox::Cancel)
+    if (QMessageBox::information(this, "INFO", msg, QMessageBox::Ok, QMessageBox::Cancel) == QMessageBox::Cancel)
       return;
   } else if (result == 1) { // custom dir
     fln = QFileDialog::getSaveFileName( this,
@@ -1422,7 +1422,7 @@ void PTextEdit::fileSavePrefs()
   if ( !fln.isEmpty() ) {
     fAdmin->savePrefs(fln);
     msg = QString("Prefs to '") + fln + QString("' saved.");
-    QMessageBox::information(nullptr, "Info", msg);
+    QMessageBox::information(nullptr, "INFO", msg);
   }
 }
 
@@ -1515,10 +1515,10 @@ void PTextEdit::fileClose(const bool check)
   int idx = fTabWidget->currentIndex();
 
   if ((fTabWidget->tabText(idx).indexOf("*")>0) && check) {
-    int result = QMessageBox::warning(this, "**WARNING**", 
+    int result = QMessageBox::warning(this, "WARNING",
                    "Do you really want to close this file.\nChanges will be lost",
-                   "Close", "Cancel");
-    if (result == 1) // Cancel
+                   QMessageBox::Close, QMessageBox::Cancel);
+    if (result == QMessageBox::Cancel)
       return;
   }
 
@@ -1545,10 +1545,10 @@ void PTextEdit::fileCloseAll()
   // check if there are any unsaved tabs
   for (int i=0; i<fTabWidget->count(); i++) {
     if (fTabWidget->tabText(i).indexOf("*") > 0) {
-      int result = QMessageBox::warning(this, "**WARNING**",
+      int result = QMessageBox::warning(this, "WARNING",
                      "Do you really want to close all files.\nChanges of unsaved files will be lost",
-                     "Close", "Cancel");
-      if (result == 1) // Cancel
+                     QMessageBox::Close, QMessageBox::Cancel);
+      if (result == QMessageBox::Cancel)
         return;
       break;
     }
@@ -1582,10 +1582,10 @@ void PTextEdit::fileCloseAllOthers()
   // check if there are any unsaved tabs
   for (int i=0; i<fTabWidget->count(); i++) {
     if (fTabWidget->tabText(i).indexOf("*") > 0) {
-      int result = QMessageBox::warning(this, "**WARNING**",
+      int result = QMessageBox::warning(this, "WARNING",
                      "Do you really want to close all files.\nChanges of unsaved files will be lost",
-                     "Close", "Cancel");
-      if (result == 1) // Cancel
+                     QMessageBox::Close, QMessageBox::Cancel);
+      if (result == QMessageBox::Cancel)
         return;
       break;
     }
@@ -1625,10 +1625,10 @@ void PTextEdit::fileExit()
   // check if there are still some modified files open
   for (int i=0; i < fTabWidget->count(); i++) {
     if (fTabWidget->tabText(i).indexOf("*") > 0) {
-      int result = QMessageBox::warning(this, "**WARNING**", 
+      int result = QMessageBox::warning(this, "WARNING",
                      "Do you really want to exit from the applcation.\nChanges will be lost",
-                     "Exit", "Cancel");
-      if (result == 1) // Cancel
+                     QMessageBox::Close, QMessageBox::Cancel);
+      if (result == QMessageBox::Cancel)
         return;
       break;
     }
@@ -1726,13 +1726,13 @@ void PTextEdit::editFind()
   }
 
   if (fFindReplaceData == nullptr) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't invoke find data structure, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke find data structure, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
     return;
   }
 
   PFindDialog *dlg = new PFindDialog(fFindReplaceData, currentEditor()->textCursor().hasSelection());
   if (dlg == nullptr) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't invoke find dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke find dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
     return;
   }
 
@@ -1818,13 +1818,13 @@ void PTextEdit::editFindAndReplace()
   }
 
   if (fFindReplaceData == nullptr) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't invoke find&replace data structure, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke find&replace data structure, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
     return;
   }
 
   PReplaceDialog *dlg = new PReplaceDialog(fFindReplaceData, currentEditor()->textCursor().hasSelection());
   if (dlg == nullptr) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't invoke find&replace dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke find&replace dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
     return;
   }
 
@@ -1998,7 +1998,7 @@ void PTextEdit::musrWiz()
 
   QProcess *proc = new QProcess(this);
   if (proc == nullptr) {
-    QMessageBox::critical(nullptr, "**ERROR**", "Couldn't invoke QProcess!");
+    QMessageBox::critical(nullptr, "ERROR", "Couldn't invoke QProcess!");
     return;
   }
 
@@ -2019,10 +2019,7 @@ void PTextEdit::musrWiz()
   if (!proc->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( nullptr,
-                           tr("Fatal error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -2044,7 +2041,7 @@ void PTextEdit::musrCalcChisq()
 
   QString tabLabel = fTabWidget->tabText(fTabWidget->currentIndex());
   if (tabLabel == "noname") {
-    QMessageBox::critical(this, "**ERROR**", "For a fit a real msr-file is needed.");
+    QMessageBox::critical(this, "ERROR", "For a fit a real msr-file is needed.");
     return;
   } else if (tabLabel == "noname*") {
     fileSaveAs();
@@ -2077,7 +2074,7 @@ void PTextEdit::musrFit()
 
   QString tabLabel = fTabWidget->tabText(fTabWidget->currentIndex());
   if (tabLabel == "noname") {
-    QMessageBox::critical(this, "**ERROR**", "For a fit a real msr-file is needed.");
+    QMessageBox::critical(this, "ERROR", "For a fit a real msr-file is needed.");
     return;
   } else if (tabLabel == "noname*") {
     fileSaveAs();
@@ -2196,7 +2193,7 @@ void PTextEdit::musrMsr2Data()
   PMsr2DataDialog *dlg = new PMsr2DataDialog(fMsr2DataParam, fAdmin->getHelpUrl("msr2data"));
 
   if (dlg == nullptr) {
-    QMessageBox::critical(this, "**ERROR**", "Couldn't invoke msr2data dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
+    QMessageBox::critical(this, "ERROR", "Couldn't invoke msr2data dialog, sorry :-(", QMessageBox::Ok, QMessageBox::NoButton);
     return;
   }
 
@@ -2218,7 +2215,7 @@ void PTextEdit::musrMsr2Data()
     // analyze parameters
     switch (dlg->getRunTag()) {
       case -1: // not valid
-        QMessageBox::critical(this, "**ERROR**",
+        QMessageBox::critical(this, "ERROR",
            "No valid run list input found :-(\nCannot do anything.",
            QMessageBox::Ok, QMessageBox::NoButton);
         return;
@@ -2231,13 +2228,13 @@ void PTextEdit::musrMsr2Data()
         fi.setFile(QFileInfo(*fFilenames.find( currentEditor() )).absolutePath() + "/" + runListFileName);
         if (!fi.exists()) {
           str = QString("Run List File '%1' doesn't exist.").arg(runListFileName);
-          QMessageBox::critical(this, "**ERROR**",
+          QMessageBox::critical(this, "ERROR",
                 str, QMessageBox::Ok, QMessageBox::NoButton);
           return;
         }
         break;
       default: // never should reach this point
-        QMessageBox::critical(this, "**ERROR**",
+        QMessageBox::critical(this, "ERROR",
            "No idea how you could reach this point.\nPlease contact the developers.",
            QMessageBox::Ok, QMessageBox::NoButton);
         return;
@@ -2428,7 +2425,7 @@ void PTextEdit::musrMsr2Data()
             file = new QFile(QFileInfo(*fFilenames.find( currentEditor() )).absolutePath() + "/" + fMsr2DataParam->runListFileName);
             if (!file->open(QIODevice::ReadOnly)) {
               str = QString("Couldn't open run list file %1, sorry.").arg(fMsr2DataParam->runListFileName);
-              QMessageBox::critical(this, "**ERROR**", str.toLatin1(), QMessageBox::Ok, QMessageBox::NoButton);
+              QMessageBox::critical(this, "ERROR", str.toLatin1(), QMessageBox::Ok, QMessageBox::NoButton);
               return;
             }
 
@@ -2478,7 +2475,7 @@ void PTextEdit::musrMsr2Data()
             file = new QFile(QFileInfo(*fFilenames.find( currentEditor() )).absolutePath() + "/" + fMsr2DataParam->runListFileName);
             if (!file->open(QIODevice::ReadOnly)) {
               str = QString("Couldn't open run list file %1, sorry.").arg(fMsr2DataParam->runListFileName);
-              QMessageBox::critical(this, "**ERROR**", str.toLatin1(), QMessageBox::Ok, QMessageBox::NoButton);
+              QMessageBox::critical(this, "ERROR", str.toLatin1(), QMessageBox::Ok, QMessageBox::NoButton);
               return;
             }
 
@@ -2526,7 +2523,7 @@ void PTextEdit::musrView()
 
   QString tabLabel = fTabWidget->tabText(fTabWidget->currentIndex());
   if (tabLabel == "noname") {
-    QMessageBox::critical(this, "**ERROR**", "For a view a real mlog/msr-file is needed.");
+    QMessageBox::critical(this, "ERROR", "For a view a real mlog/msr-file is needed.");
     return;
   } else if (tabLabel == "noname*") {
     fileSaveAs();
@@ -2578,10 +2575,7 @@ void PTextEdit::musrView()
   if (!proc->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( nullptr,
-                           tr("Fatal error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -2599,7 +2593,7 @@ void PTextEdit::musrViewFinished(int exitCode, QProcess::ExitStatus)
     msg += QString("* cannot read data-file.\n");
     msg += QString("* many more things can go wrong.\n");
     msg += QString("Please check!");
-    QMessageBox::critical(nullptr, tr("Fatal Error"), msg, tr("Quit"));
+    QMessageBox::critical(nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close);
   }
 }
 
@@ -2614,7 +2608,7 @@ void PTextEdit::musrT0()
 
   QString tabLabel = fTabWidget->tabText(fTabWidget->currentIndex());
   if (tabLabel == "noname") {
-    QMessageBox::critical(this, "**ERROR**", "For a view a real mlog/msr-file is needed.");
+    QMessageBox::critical(this, "ERROR", "For a view a real mlog/msr-file is needed.");
     return;
   } else if (tabLabel == "noname*") {
     fileSaveAs();
@@ -2653,10 +2647,7 @@ void PTextEdit::musrT0()
   if (!proc->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( nullptr,
-                           tr("Fatal error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -2672,7 +2663,7 @@ void PTextEdit::musrFT()
   PGetMusrFTOptionsDialog *dlg = new PGetMusrFTOptionsDialog(*fFilenames.find( currentEditor() ), fMusrFTPrevCmd, fAdmin->getHelpUrl("musrFT"));
 
   if (dlg == nullptr) {
-    QMessageBox::critical(this, "**ERROR** musrFT", "Couldn't invoke musrFT Options Dialog.");
+    QMessageBox::critical(this, "ERROR musrFT", "Couldn't invoke musrFT Options Dialog.");
     return;
   }
 
@@ -2693,10 +2684,7 @@ void PTextEdit::musrFT()
     if (!proc->waitForStarted()) {
       // error handling
       QString msg(tr("Could not execute the output command: ")+cmd[0]);
-      QMessageBox::critical( nullptr,
-                             tr("Fatal error"),
-                             msg,
-                             tr("Quit") );
+      QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
       return;
     }
   }
@@ -2714,7 +2702,7 @@ void PTextEdit::musrPrefs()
   PPrefsDialog *dlg = new PPrefsDialog(fAdmin);
 
   if (dlg == nullptr) {
-    QMessageBox::critical(this, "**ERROR** musrPrefs", "Couldn't invoke Preferences Dialog.");
+    QMessageBox::critical(this, "ERROR musrPrefs", "Couldn't invoke Preferences Dialog.");
     return;
   }
 
@@ -2770,7 +2758,7 @@ void PTextEdit::musrSetSteps()
   // make sure I have a saved msr-file to work on
   QString tabLabel = fTabWidget->tabText(fTabWidget->currentIndex());
   if (tabLabel == "noname") {
-    QMessageBox::critical(this, "**ERROR**", "For musrStep a real mlog/msr-file is needed.");
+    QMessageBox::critical(this, "ERROR", "For musrStep a real mlog/msr-file is needed.");
     return;
   } else if (tabLabel == "noname*") {
     fileSaveAs();
@@ -2796,7 +2784,7 @@ void PTextEdit::musrSetSteps()
 
   QProcess *proc = new QProcess(this);
   if (proc == nullptr) {
-    QMessageBox::critical(nullptr, "**ERROR**", "Couldn't invoke QProcess!");
+    QMessageBox::critical(nullptr, "ERROR", "Couldn't invoke QProcess!");
     return;
   }
 
@@ -2817,10 +2805,7 @@ void PTextEdit::musrSetSteps()
   if (!proc->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd[0]);
-    QMessageBox::critical( nullptr,
-                           tr("Fatal error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -2984,10 +2969,7 @@ void PTextEdit::mupp()
   if (!proc->waitForStarted()) {
     // error handling
     QString msg(tr("Could not execute the output command: ")+cmd);
-    QMessageBox::critical( nullptr,
-                           tr("Fatal error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
     return;
   }
 }
@@ -3001,10 +2983,7 @@ void PTextEdit::helpContents()
   bool ok = QDesktopServices::openUrl(QUrl(fAdmin->getHelpUrl("main"), QUrl::TolerantMode));
   if (!ok) {
     QString msg = QString("<p>Sorry: Couldn't open default web-browser for the help.<br>Please try: <a href=\"%1\">musrfit docu</a> in your web-browser.").arg(fAdmin->getHelpUrl("main"));
-    QMessageBox::critical( nullptr,
-                           tr("Fatal Error"),
-                           msg,
-                           tr("Quit") );
+    QMessageBox::critical( nullptr, tr("FATAL ERROR"), msg, QMessageBox::Close );
   }
 }
 
@@ -3037,7 +3016,7 @@ void PTextEdit::helpAboutQt()
 void PTextEdit::exitStatusMusrWiz(int exitCode, QProcess::ExitStatus exitStatus)
 {
   if (exitStatus == QProcess::CrashExit) {
-    QMessageBox::critical(nullptr, "**FATAL**", "musrWiz returned CrashExit.");
+    QMessageBox::critical(nullptr, "FATAL ERROR", "musrWiz returned CrashExit.");
     return;
   }
 
@@ -3053,7 +3032,7 @@ void PTextEdit::exitStatusMusrWiz(int exitCode, QProcess::ExitStatus exitStatus)
   std::ifstream fin(pathName.toLatin1().data(), std::ifstream::in);
   if (!fin.is_open()) {
     errMsg = QString("PTextEdit::exitStatusMusrWiz: couldn't read %1 file.").arg(pathName);
-    QMessageBox::critical(nullptr, "**ERROR**", errMsg);
+    QMessageBox::critical(nullptr, "ERROR", errMsg);
     return;
   }
   char line[128];
@@ -3088,7 +3067,7 @@ void PTextEdit::exitStatusMusrWiz(int exitCode, QProcess::ExitStatus exitStatus)
   QFile logFile(pathName);
   if (!logFile.remove()) {
     errMsg = QString("PTextEdit::exitStatusMusrWiz: couldn't delete %1 file.").arg(pathName);
-    QMessageBox::critical(nullptr, "**ERROR**", errMsg);
+    QMessageBox::critical(nullptr, "ERROR", errMsg);
   }
 }
 
@@ -3101,7 +3080,7 @@ void PTextEdit::exitStatusMusrWiz(int exitCode, QProcess::ExitStatus exitStatus)
 void PTextEdit::exitStatusMusrSetSteps(int exitCode, QProcess::ExitStatus exitStatus)
 {
   if (exitStatus == QProcess::CrashExit) {
-    QMessageBox::critical(nullptr, "**FATAL**", "musrStep returned CrashExit.");
+    QMessageBox::critical(nullptr, "FATAL ERROR", "musrStep returned CrashExit.");
     return;
   }
 
@@ -3260,7 +3239,7 @@ void PTextEdit::fileChanged(const QString &fileName)
   fFileSystemWatcherActive = false;
 
   QString str = "File '" + fileName + "' changed on the system.\nDo you want to reload it?";
-  int result = QMessageBox::question(this, "**INFO**", str, QMessageBox::Yes, QMessageBox::No);
+  int result = QMessageBox::question(this, "INFO", str, QMessageBox::Yes, QMessageBox::No);
   if (result == QMessageBox::Yes) {
     // find correct file
     int idx = -1;