Index: tol/btol/bgrammar/nameblock.cpp
===================================================================
--- tol/btol/bgrammar/nameblock.cpp	(revision f92b670ac104161b64d596b2415a9e86678cf9cc)
+++ tol/btol/bgrammar/nameblock.cpp	(revision 7c3619c3550364381c2c6f99d1eae7f368450d4f)
@@ -218,5 +218,8 @@
   for(n=1; n<=set_.Card(); n++)
 	{
-    set_[n]->PutNameBlock(NULL);
+    if(set_[n])
+    { 
+      set_[n]->PutNameBlock(NULL);
+    }
   }
   public_.clear();