--- a/UIPainterView.st	Mon Feb 15 21:13:28 1999 +0100
+++ b/UIPainterView.st	Wed Feb 17 11:55:19 1999 +0100
@@ -1225,17 +1225,23 @@
 
     Cursor wait showWhile: [
         self removeAll.
-        spec    := UISpecification from:specOrSpecArray.
+        specOrSpecArray notNil ifTrue:[
+            spec    := UISpecification from:specOrSpecArray.
+        ].
         builder := UIBuilder new isEditing:true.
         "set applicationClass, in order that subspecifications may be resolved"
         className notNil ifTrue:[
             builder applicationClass:(self resolveName:className).
         ].
-        spec window setupView:self topView for:builder.
-        self addSpec:(spec component) builder:builder in:self.
+        spec notNil ifTrue:[
+            spec window setupView:self topView for:builder.
+            self addSpec:(spec component) builder:builder in:self.
+        ].
         self realizeAllSubViews.
         inputView raise.
-        treeView setAttributesFromWindowSpec:(spec window)
+        spec notNil ifTrue:[
+            treeView setAttributesFromWindowSpec:(spec window)
+        ]
     ]
 
 !