--- a/UIPainterView.st	Mon Mar 08 12:23:10 1999 +0100
+++ b/UIPainterView.st	Tue Mar 09 16:56:38 1999 +0100
@@ -1153,7 +1153,7 @@
             , '\\    "\'
             , ('     UIPainter new openOnClass:' , className , ' andSelector:#' , methodName , '\').
 
-    (cls isSubclassOf:ApplicationModel) ifTrue:[
+    (cls notNil and:[cls isSubclassOf:ApplicationModel]) ifTrue:[
         code := code
             , ('     ' , className , ' new openInterface:#' , methodName , '\').
     ].