Index: tol/btol/set_type/setgra.cpp
===================================================================
--- tol/btol/set_type/setgra.cpp	(revision 8e8d667e24527b1344e33886650859c47e304eb7)
+++ tol/btol/set_type/setgra.cpp	(revision ec6e142d6135d513bf80020fb2d2a9edb3c2eeef)
@@ -1696,5 +1696,5 @@
   BInt		     n	    = 1;
    
-  if(code.Operator()->NumArg()!=1)
+  if(!code.Operator() || (code.Operator()->NumArg()!=1))
   {
 	  Error(I2("Wrong argument function in EvalSet function calling."