diff --git a/src/classes/PFitterFcnDKS.cpp b/src/classes/PFitterFcnDKS.cpp
index 7c7909b2..cd5238a2 100644
--- a/src/classes/PFitterFcnDKS.cpp
+++ b/src/classes/PFitterFcnDKS.cpp
@@ -95,10 +95,16 @@ Double_t PFitterFcnDKS::operator()(const std::vector<Double_t>& par) const
     ierr += fDKS.callSetConsts(dksp.fN0, dksp.fTau, dksp.fNbkg);
 
     // set fun values
-    ierr += fDKS.writeFunctions(&dksp.fFun[0], dksp.fFun.size());
+    if (dksp.fFun.size() == 0)
+      ierr += fDKS.writeFunctions(nullptr, 0);
+    else
+      ierr += fDKS.writeFunctions(&dksp.fFun[0], dksp.fFun.size());
 
     // set map values
-    ierr += fDKS.writeMaps(&dksp.fMap[0], dksp.fMap.size());
+    if (dksp.fMap.size() == 0)
+      ierr += fDKS.writeMaps(nullptr, 0);
+    else
+      ierr += fDKS.writeMaps(&dksp.fMap[0], dksp.fMap.size());
 
     // calc chisq/log-mlh
     chisq = 0.0;
@@ -122,10 +128,16 @@ Double_t PFitterFcnDKS::operator()(const std::vector<Double_t>& par) const
     ierr += fDKS.callSetConsts(dksp.fAlpha, dksp.fBeta);
 
     // set fun values
-    ierr += fDKS.writeFunctions(&dksp.fFun[0], dksp.fFun.size());
+    if (dksp.fFun.size() == 0)
+      ierr += fDKS.writeFunctions(nullptr, 0);
+    else
+      ierr += fDKS.writeFunctions(&dksp.fFun[0], dksp.fFun.size());
 
     // set map values
-    ierr += fDKS.writeMaps(&dksp.fMap[0], dksp.fMap.size());
+    if (dksp.fMap.size() == 0)
+      ierr += fDKS.writeMaps(nullptr, 0);
+    else 
+      ierr += fDKS.writeMaps(&dksp.fMap[0], dksp.fMap.size());
 
     // calc chisq
     chisq = 0.0;
@@ -318,7 +330,6 @@ void PFitterFcnDKS::InitDKS(const UInt_t dksTag)
   }
 
   // now ready to init the chisq buffer on the GPU
-//  std::cout << "debug> maximal packed histo size=" << maxSize << ", parSize=" << parSize << ", funSize=" << funSize << ", mapSize=" << mapSize << std::endl;
   ierr = fDKS.initChiSquare(maxSize, parSize, funSize, mapSize);
   if (ierr != 0) {
     std::cerr << ">> PFitterFcnDKS::InitDKS: **ERROR** failed to allocate the necessary chisq buffer on the GPU." << std::endl;
@@ -381,10 +392,9 @@ void PFitterFcnDKS::InitDKS(const UInt_t dksTag)
       fValid = false;
       return;
     }
-    startTimeBin = fRunListCollection->GetStartTimeBin(MSR_FITTYPE_ASYM, i); //as35
-    endTimeBin   = fRunListCollection->GetEndTimeBin(MSR_FITTYPE_ASYM, i); //as35
+    startTimeBin = fRunListCollection->GetStartTimeBin(MSR_FITTYPE_ASYM, i);
+    endTimeBin   = fRunListCollection->GetEndTimeBin(MSR_FITTYPE_ASYM, i);
     length = endTimeBin-startTimeBin;
-std::cout << "debug> length=" << length << std::endl; //as35
     if (startTimeBin < 0) {
       std::cerr << ">> PFitterFcnDKS::InitDKS: **ERROR** startTimeBin undefind (asymmetry fit)." << std::endl;
       fValid = false;