Index: trunk/MagicSoft/Mars/mjobs/MDataSet.cc
===================================================================
--- trunk/MagicSoft/Mars/mjobs/MDataSet.cc	(revision 8220)
+++ trunk/MagicSoft/Mars/mjobs/MDataSet.cc	(revision 8221)
@@ -301,4 +301,5 @@
     TIter Next(const_cast<TList*>(&list));
     TObject *o=0;
+
     while ((o=Next()))
     {
@@ -314,5 +315,6 @@
 
         const TString dir(o->GetTitle());
-        seq.SetupDatRuns(files, MSequence::kImages, dir.IsNull() ? 0 : dir.Data());
+        if (seq.SetupDatRuns(files, MSequence::kImages, dir.IsNull() ? 0 : dir.Data())<=0)
+            return kFALSE;
     }
 
Index: trunk/MagicSoft/Mars/mjobs/MSequence.cc
===================================================================
--- trunk/MagicSoft/Mars/mjobs/MSequence.cc	(revision 8220)
+++ trunk/MagicSoft/Mars/mjobs/MSequence.cc	(revision 8221)
@@ -203,6 +203,8 @@
     TString d(path);
 
+    const Bool_t def = d.IsNull();
+
     // Setup path
-    if (d.IsNull())
+    if (def)
     {
         d = GetStandardPath();
@@ -289,5 +291,29 @@
     }
 
-    return iter.GetNumEntries();
+    const Int_t n0 = iter.GetNumEntries();
+    const Int_t n1 = arr.GetSize();
+    if (n0==0)
+    {
+        *fLog << err;
+        *fLog < "ERROR - No input files for sequence #" << GetSequence() << endl;
+        *fLog << "        read from " << GetName() << endl;
+        *fLog << "        found in" << (def?" default-path ":" ") << d << endl;
+        return 0;
+    }
+
+    if (n0==n1)
+        return n0;
+
+    *fLog << err;
+    *fLog << "ERROR - " << n0 << " input files for sequence #" << GetSequence() << " found in" << endl;
+    *fLog << "        " << (def?" default-path ":" ") << d << endl;
+    *fLog << "        but " << n1 << " files were defined in sequence file" << endl;
+    *fLog << "        " << GetName() << endl;
+    if (fLog->GetDebugLevel()<=4)
+        return 0;
+
+    *fLog << dbg << "Files which are searched for this sequence:" << endl;
+    iter.Print();
+    return 0;
 }