diff --git a/src/addRun.cpp b/src/addRun.cpp
index 5c5ada53..d56b65cf 100644
--- a/src/addRun.cpp
+++ b/src/addRun.cpp
@@ -797,5 +797,8 @@ int main(int argc, char *argv[])
     }
   }
 
+  if (!isGood)
+    return PMUSR_DATA_FILE_READ_ERROR;
+
   return PMUSR_SUCCESS;
 }
diff --git a/src/any2many.cpp b/src/any2many.cpp
index f3f78dfd..9b4cc874 100644
--- a/src/any2many.cpp
+++ b/src/any2many.cpp
@@ -533,6 +533,7 @@ int main(int argc, char *argv[])
   bool success = dataHandler->IsAllDataAvailable();
   if (!success) {
     std::cerr << std::endl << ">> any2many **ERROR** Couldn't read all data files, will quit ..." << std::endl;
+    return PMUSR_DATA_FILE_READ_ERROR;
   }
 
   return PMUSR_SUCCESS;
diff --git a/src/dump_header.cpp b/src/dump_header.cpp
index 1897c33d..d7285bab 100644
--- a/src/dump_header.cpp
+++ b/src/dump_header.cpp
@@ -1083,21 +1083,23 @@ int main(int argc, char *argv[])
 
   boost::to_lower(fileFormat);
 
+  int status = 0;
   if (boost::iequals(fileFormat, "MusrRoot") || boost::iequals(fileFormat, "ROOT")) {
-    dump_header_root(pathFln, summary, counts);
+    status = dump_header_root(pathFln, summary, counts);
   } else if (boost::iequals(fileFormat, "NeXus")) {
 #ifdef PNEXUS_ENABLED
-    dump_header_nexus(pathFln, counts);
+    status = dump_header_nexus(pathFln, counts);
 #else
     std::cout << std::endl << "Sorry, NeXus is not enabled, hence I cannot help you." << std::endl;
+    status = 1;
 #endif
   } else if (boost::iequals(fileFormat, "PSI-BIN") || boost::iequals(fileFormat, "PSI-MDU")) {
-    dump_header_psi_bin(pathFln, fileFormat, counts);
+    status = dump_header_psi_bin(pathFln, fileFormat, counts);
   } else if (boost::iequals(fileFormat, "MUD")) {
-    dump_header_mud(pathFln, counts);
+    status = dump_header_mud(pathFln, counts);
   } else if (boost::iequals(fileFormat, "WKM")) {
-    dump_header_wkm(pathFln);
+    status = dump_header_wkm(pathFln);
   }
 
-  return 0;
+  return status;
 }
diff --git a/src/msr2data.cpp b/src/msr2data.cpp
index 6044e1e8..8408f2c1 100644
--- a/src/msr2data.cpp
+++ b/src/msr2data.cpp
@@ -1005,5 +1005,5 @@ int main(int argc, char *argv[])
 
   std::cout << std::endl << ">> msr2data: done ..." << std::endl;
 
-  return 1;
+  return 0;
 }
diff --git a/src/msr2msr.cpp b/src/msr2msr.cpp
index 30b8eca9..14242bcc 100644
--- a/src/msr2msr.cpp
+++ b/src/msr2msr.cpp
@@ -676,12 +676,13 @@ int main(int argc, char *argv[])
 
   // check if conversion seems to be OK
   if (!success) {
+    std::cerr << std::endl << "**ERROR** conversion of " << argv[1] << " failed, removing " << argv[2] << "." << std::endl;
     std::error_code ec;
     std::filesystem::remove_all(std::filesystem::path(argv[2]), ec);
     if (ec) {
       std::cerr << "**ERROR** couldn't remove " << argv[2] << ": " << ec.message() << std::endl;
-      return 0;
     }
+    return 1;
   }
 
   if (theoryTag != -1) {
@@ -690,5 +691,5 @@ int main(int argc, char *argv[])
 
   std::cout << std::endl << "done ..." << std::endl;
 
-  return 1;
+  return 0;
 }
diff --git a/src/musrFT.cpp b/src/musrFT.cpp
index 4934bcf3..db5ea13b 100644
--- a/src/musrFT.cpp
+++ b/src/musrFT.cpp
@@ -1449,6 +1449,8 @@ Int_t main(Int_t argc, Char_t *argv[])
 
   std::unique_ptr<PFourierCanvas> fourierCanvas;
 
+  Int_t result = PMUSR_SUCCESS;
+
   // if Fourier dumped if whished do it now
   if (startupParam.dumpFln.Length() > 0) {
     musrFT_dumpData(startupParam.dumpFln, fourier, startupParam.fourierRange[0], startupParam.fourierRange[1]);
@@ -1495,6 +1497,7 @@ Int_t main(Int_t argc, Char_t *argv[])
       std::cerr << std::endl << ">> musrFT **SEVERE ERROR** Couldn't invoke all necessary objects, will quit.";
       std::cerr << std::endl;
       ok = false;
+      result = PMUSR_MSR_RUN_ERROR;
     } else {
       // connect signal/slot
       TQObject::Connect("TCanvas", "Closed()", "PFourierCanvas", fourierCanvas.get(), "LastCanvasClosed()");
@@ -1524,5 +1527,5 @@ Int_t main(Int_t argc, Char_t *argv[])
       app.Run();
   }
 
-  return PMUSR_SUCCESS;
+  return result;
 }
diff --git a/src/musrRootValidation.cpp b/src/musrRootValidation.cpp
index 9185fe8a..0b6e78d4 100644
--- a/src/musrRootValidation.cpp
+++ b/src/musrRootValidation.cpp
@@ -680,10 +680,13 @@ int main(int argc, char *argv[])
     return -1;
   }
 
+  bool valid = true;
+
   if (is_valid(doc, argv[2])) {
     std::cout << std::endl << "xml-file " << argv[1] << " validates against xml-schema " << argv[2] << std::endl << std::endl;
   } else {
     std::cerr << std::endl << "**ERROR** xml-file " << argv[1] << " fails to validate against xml-schema " << argv[2] << std::endl << std::endl;
+    valid = false;
   }
 
   // do some further consistency checks
@@ -692,6 +695,7 @@ int main(int argc, char *argv[])
     std::cerr << std::endl << "  with the header; found " << dump.GetNoOfDecayHistos() << " histograms in the DecayAnaModule,";
     std::cerr << std::endl << "  but in the header: No of Histos = " << dump.GetNoOfHistos() << "; # RedGreen Offsets = " << dump.GetNoOfRedGreenOffsets();
     std::cerr << std::endl << std::endl;
+    valid = false;
   }
 
   if (dump.GetNoOfDecayHistos() != dump.GetNoOfDetectors()) {
@@ -700,7 +704,11 @@ int main(int argc, char *argv[])
     std::cerr << std::endl << "  Found " << dump.GetNoOfDecayHistos() << " histograms in the DecayAnaModule,";
     std::cerr << std::endl << "  but " << dump.GetNoOfDetectors() << " number of Detector entries.";
     std::cerr << std::endl << std::endl;
+    valid = false;
   }
 
+  if (!valid)
+    return -1;
+
   return 0;
 }
diff --git a/src/musrfit.cpp b/src/musrfit.cpp
index 61185d49..0eeca6aa 100644
--- a/src/musrfit.cpp
+++ b/src/musrfit.cpp
@@ -700,9 +700,12 @@ int main(int argc, char *argv[])
 
   dataHandler->ReadData();
 
+  int result = PMUSR_SUCCESS;
+
   bool success = dataHandler->IsAllDataAvailable();
   if (!success) {
     std::cerr << std::endl << ">> musrfit **ERROR** Couldn't read all data files, will quit ..." << std::endl;
+    result = PMUSR_DATA_FILE_READ_ERROR;
   }
 
   // if present, replace the run title of the <msr-file> with the run title of the FIRST run in the run block of the msr-file
@@ -711,12 +714,14 @@ int main(int argc, char *argv[])
     if (rl->empty()) {
       success = false;
       std::cerr << std::endl << ">> musrfit **ERROR** no run list present." << std::endl;
+      result = PMUSR_MSR_RUN_ERROR;
     }
     if (success) {
       TString *name = rl->at(0).GetRunName();
       if (name == nullptr) {
         std::cerr << std::endl << ">> musrfit **ERROR** to obtain run list name." << std::endl;
         success = false;
+        result = PMUSR_MSR_RUN_ERROR;
       }
       PRawRunData *rrd = nullptr;
       if (success) {
@@ -724,6 +729,7 @@ int main(int argc, char *argv[])
         if (rrd == nullptr) {
           std::cerr << std::endl << ">> musrfit **ERROR** no raw run data avaliable." << std::endl;
           success = false;
+          result = PMUSR_MSR_RUN_ERROR;
         }
       }
       if (success) {
@@ -736,13 +742,14 @@ int main(int argc, char *argv[])
   // generate the necessary fit histogramms for the fit
   std::unique_ptr<PRunListCollection> runListCollection;
   if (success) {
-    // feed all the necessary histogramms for the fit   
+    // feed all the necessary histogramms for the fit
     runListCollection = std::make_unique<PRunListCollection>(msrHandler.get(), dataHandler.get());
     for (unsigned int i=0; i < msrHandler->GetMsrRunList()->size(); i++) {
       success = runListCollection->Add(i, kFit);
       if (!success) {
         std::cout << std::endl << ">> musrfit **ERROR** Couldn't handle run no " << i+1 << ": ";
         std::cout << (*msrHandler->GetMsrRunList())[i].GetRunName()->Data();
+        result = PMUSR_MSR_RUN_ERROR;
         break;
       }
     }
@@ -840,7 +847,7 @@ int main(int argc, char *argv[])
 
   std::cout << std::endl << "done ..." << std::endl;
 
-  return PMUSR_SUCCESS;
+  return result;
 }
 
 // end ---------------------------------------------------------------------
diff --git a/src/musrt0.cpp b/src/musrt0.cpp
index 0f6a8909..192f30d0 100644
--- a/src/musrt0.cpp
+++ b/src/musrt0.cpp
@@ -312,6 +312,8 @@ Int_t main(Int_t argc, Char_t *argv[])
   }
   msrHandler->CopyMsrStatisticBlock(); // just copy the statistics block since no fit is performed
 
+  Int_t result = PMUSR_SUCCESS;
+
   // check if the fittype is not NonMusr
   PMsrRunList *runList = msrHandler->GetMsrRunList();
   for (UInt_t i=0; i<runList->size(); i++) {
@@ -322,6 +324,7 @@ Int_t main(Int_t argc, Char_t *argv[])
     if (fitType == MSR_FITTYPE_NON_MUSR) {
       std::cout << std::endl << ">> musrt0 **ERROR** t0 setting for NonMusr fit type doesn't make any sense, will quit ..." << std::endl;
       success = false;
+      result = PMUSR_UNSUPPORTED_FEATURE;
       break;
     }
   }
@@ -339,6 +342,7 @@ Int_t main(Int_t argc, Char_t *argv[])
     success = dataHandler->IsAllDataAvailable();
     if (!success) {
       std::cout << std::endl << ">> musrt0 **ERROR** Couldn't read all data files, will quit ..." << std::endl;
+      result = PMUSR_DATA_FILE_READ_ERROR;
     }
   }
 
@@ -1160,6 +1164,9 @@ Int_t main(Int_t argc, Char_t *argv[])
     }
   }
 
+  if (!success)
+    return result;
+
   // write msr-file
   msrHandler->WriteMsrLogFile(false);
 
diff --git a/src/musrview.cpp b/src/musrview.cpp
index 2f629414..dd8a1ac1 100644
--- a/src/musrview.cpp
+++ b/src/musrview.cpp
@@ -369,6 +369,7 @@ int main(int argc, char *argv[])
         if (show_errMsgBox)
           musrview_error_msg(errMsg.str());
         ok = false;
+        result = PMUSR_MSR_RUN_ERROR;
         break;
       }
       if (!musrCanvas->IsValid()) {
@@ -377,6 +378,7 @@ int main(int argc, char *argv[])
         if (show_errMsgBox)
           musrview_error_msg(errMsg.str());
         ok = false;
+        result = PMUSR_MSR_RUN_ERROR;
         delete musrCanvas;
         break;
       }
@@ -393,6 +395,7 @@ int main(int argc, char *argv[])
 
       if (!musrCanvas->IsValid()) { // something went wrong
         ok = false;
+        result = PMUSR_MSR_RUN_ERROR;
         break;
       }
 
diff --git a/src/write_musrRoot_runHeader.cpp b/src/write_musrRoot_runHeader.cpp
index 30992c0f..0e8cd154 100644
--- a/src/write_musrRoot_runHeader.cpp
+++ b/src/write_musrRoot_runHeader.cpp
@@ -245,8 +245,11 @@ int main(int argc, char *argv[])
   // root file header related things
   TFolder *runHeader = new TFolder("RunHeader", "MusrRoot Run Header Info");
 
-  if (header->FillFolder(runHeader)) {
+  bool success = header->FillFolder(runHeader);
+  if (success) {
     runHeader->Write();
+  } else {
+    std::cerr << std::endl << "**ERROR** couldn't fill the MusrRoot run header folder." << std::endl;
   }
 
   f->Close();
@@ -255,5 +258,8 @@ int main(int argc, char *argv[])
   delete f;
   delete header;
 
+  if (!success)
+    return -1;
+
   return 0;
 }