Index: generic/nsfStack.c
===================================================================
diff -u -rcec13372cd20131e3283e5ec1c864d734441ba61 -re2fe47226a0bb0c420173a9590309645e5a0592a
--- generic/nsfStack.c	(.../nsfStack.c)	(revision cec13372cd20131e3283e5ec1c864d734441ba61)
+++ generic/nsfStack.c	(.../nsfStack.c)	(revision e2fe47226a0bb0c420173a9590309645e5a0592a)
@@ -312,7 +312,9 @@
      */ 
     if ((cscPtr->callType & NSF_CSC_CALL_IS_ENSEMBLE) == 0) break;
   }
-  *framePtrPtr = varFramePtr;
+  if (framePtrPtr) {
+    *framePtrPtr = varFramePtr;
+  }
   
   return cscPtr;
 }