Index: trunk/MagicSoft/Mars/mdata/MDataChain.cc
===================================================================
--- trunk/MagicSoft/Mars/mdata/MDataChain.cc	(revision 1332)
+++ trunk/MagicSoft/Mars/mdata/MDataChain.cc	(revision 1334)
@@ -103,4 +103,5 @@
 
 MDataChain::MDataChain(const char *rule, const char *name, const char *title)
+    : fOperatorType(kENoop)
 {
     fName  = name  ? name  : "MDataChain";
@@ -382,5 +383,8 @@
 {
     if (!fMember)
+    {
+        *fLog << warn << "MDataChain not valid." << endl;
         return 0;
+    }
 
     const Double_t val = fMember->GetValue();
@@ -405,4 +409,6 @@
     case kENoop:  return val;
     }
+
+    *fLog << warn << "No Case for " << fOperatorType << " available." << endl;
 
     return 0;
Index: trunk/MagicSoft/Mars/mdata/MDataMember.cc
===================================================================
--- trunk/MagicSoft/Mars/mdata/MDataMember.cc	(revision 1332)
+++ trunk/MagicSoft/Mars/mdata/MDataMember.cc	(revision 1334)
@@ -68,5 +68,9 @@
 {
     if (!fCall)
+    {
+        *fLog << err << "No TMethodCall for " << fName << " of ";
+        *fLog << fObject->GetName() << " available... returning 0." << endl;
         return 0;
+    }
 
     switch (fCall->ReturnType())
@@ -84,5 +88,5 @@
     default:
         *fLog << err << "DataMember " << fName << " of ";
-        *fLog << fObject->GetName() << " neither int nor float... abort." << endl;
+        *fLog << fObject->GetName() << " neither int nor float... returning 0." << endl;
         return 0;
     }