--- a/AbstractHierarchicalItem.st	Mon Feb 18 18:36:47 2019 +0100
+++ b/AbstractHierarchicalItem.st	Mon Feb 18 18:38:46 2019 +0100
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 1999/2015 by eXept Software AG
               All Rights Reserved
@@ -493,7 +495,7 @@
             wasExpanded := toExpand isExpanded.
             (wasExpanded or:[toExpand canExpand]) ifTrue:[
                 toExpand setExpanded:true.
-                prevChildren := toExpand getChildren.
+                prevChildren := toExpand getChildren ? #().
                 childrenOfToExpand := toExpand children.
 
                 index := toExpand listIndex.    "/ get the visible list index
@@ -535,7 +537,7 @@
     "/ self checkConsistency.
 
     "Modified (comment): / 02-08-2018 / 16:16:17 / Stefan Vogel"
-    "Modified: / 13-02-2019 / 12:59:19 / Claus Gittinger"
+    "Modified: / 18-02-2019 / 18:37:36 / Claus Gittinger"
 !
 
 recursiveToggleExpand
@@ -1855,7 +1857,7 @@
         toCollapse := todo removeFirst.
         
         toCollapse setExpanded:false.
-        toCollapse getChildren do:[:eachChild |
+        (toCollapse getChildren ? #()) do:[:eachChild |
             eachChild canRecursiveCollapse ifTrue:[
                 todo add:eachChild
             ].    
@@ -1863,7 +1865,7 @@
     ].
 
     "Modified: / 02-08-2018 / 16:07:35 / Stefan Vogel"
-    "Modified (format): / 13-02-2019 / 12:15:00 / Claus Gittinger"
+    "Modified: / 18-02-2019 / 18:37:49 / Claus Gittinger"
 !
 
 recursiveSetExpandedAndAddToList:aList