--- a/Tools__NewSystemBrowser.st	Tue Dec 27 11:03:07 2016 +0100
+++ b/Tools__NewSystemBrowser.st	Tue Dec 27 11:36:16 2016 +0100
@@ -53408,10 +53408,12 @@
     ] ifFalse:[
         menu := self menuFor: selector.
         menu itemsDo:[:item|
-            | selector |
-
-            selector := item value.
-            item itemValue:[self perform: selector with: item argument with: manager]
+            | eachSelector |
+
+            eachSelector := item value.
+            eachSelector notNil ifTrue:[
+                item itemValue:[self perform: eachSelector with: item argument with: manager]
+            ].
         ]
     ].
     self replaceSourceCodeManagerPlaceholderWith: manager in: menu.