Index: generic/nsf.c
===================================================================
diff -u -r54277a59a45fb6f055637b9a0e14a2fefd31f7eb -r9bd2c31a189868ce6564005d7b5a7cf9e0dc81a5
--- generic/nsf.c	(.../nsf.c)	(revision 54277a59a45fb6f055637b9a0e14a2fefd31f7eb)
+++ generic/nsf.c	(.../nsf.c)	(revision 9bd2c31a189868ce6564005d7b5a7cf9e0dc81a5)
@@ -26063,7 +26063,7 @@
   }
 
   result = Tcl_ListObjGetElements(interp, arglistObj, &objc, &objv);
-  if (likely(result == TCL_OK)) {
+  if (likely(result == TCL_OK) && parsedParam.paramDefs != NULL) {
     ParseContext  pc;
     NsfParamDefs *paramDefs = parsedParam.paramDefs;
     unsigned int  processFlags = 0u;