--- a/app/view/widget/Netzbetreiber.js	Fri May 27 14:52:56 2016 +0200
+++ b/app/view/widget/Netzbetreiber.js	Thu Jun 02 12:30:14 2016 +0200
@@ -39,6 +39,9 @@
 
     getValue: function() {
         var value = this.down('combobox').getValue();
+        if (value === undefined || value === null || value === '') {
+            return [];
+        }
         if (value instanceof Array) {
             return value;
         }