Index: trunk/MadWeight/Analysis.C
===================================================================
--- trunk/MadWeight/Analysis.C	(revision 18)
+++ trunk/MadWeight/Analysis.C	(revision 21)
@@ -11,4 +11,5 @@
 #include "TChain.h"
 #include "TString.h"
+#include "TClonesArray.h"
 
 #include "TH2.h"
@@ -263,9 +264,13 @@
   ExRootMissingET *input, *output;
 
-  input = static_cast<ExRootMissingET*>(fInputMissingET->At(0));
-
-  output = static_cast<ExRootMissingET*>(fOutputMissingET->NewEntry());
-
-  *output = *input;
+  if(fInputMissingET->GetEntriesFast() > 0)
+  {
+    input = static_cast<ExRootMissingET*>(fInputMissingET->At(0));
+  
+  
+    output = static_cast<ExRootMissingET*>(fOutputMissingET->NewEntry());
+  
+    *output = *input;
+  }
 }