Index: src/main/resources/scripts/migration/from4_4To4_5/util/BuildDialogIdMap.groovy
===================================================================
--- src/main/resources/scripts/migration/from4_4To4_5/util/BuildDialogIdMap.groovy	(revision 55696)
+++ src/main/resources/scripts/migration/from4_4To4_5/util/BuildDialogIdMap.groovy	(working copy)
@@ -65,8 +65,10 @@
   def initDialogPathMap(){
     initParam()
     hm = MgnlContext.getHierarchyManager('config')
-    def dialogContent = hm.getContent(dialogPath)
-    populateDialogPathMap(dialogContent, "")
+    if (hm.isExist(dialogPath)) {
+      def dialogContent = hm.getContent(dialogPath)
+      populateDialogPathMap(dialogContent, "")
+    }
     return dialogPathMap
   }