diff --git a/app/DD-Record-Organizer/frmNodeNavigation.vb b/app/DD-Record-Organizer/frmNodeNavigation.vb
index 7416466..b28b823 100644
--- a/app/DD-Record-Organizer/frmNodeNavigation.vb
+++ b/app/DD-Record-Organizer/frmNodeNavigation.vb
@@ -936,11 +936,14 @@ LOGGER.Error(ex)
             ' LINQ für Zugriff auf DT_VWPMO_CONSTRUCTOR_FORMS
             Dim result1 = (From form In DT_CONTROLS_ENTITY.AsEnumerable()
                            Select form
-                           Where form.Item("CONTROL_ID") = CONTROL_ID).Single()
-            Dim locked = result1.Item("CONTROL_READ_ONLY")
-            If state = False And locked = True Then
-                state = True
+                           Where form.Item("CONTROL_ID") = CONTROL_ID).SingleOrDefault()
+            If Not IsNothing(result1) Then
+                Dim locked = result1.Item("CONTROL_READ_ONLY")
+                If state = False And locked = True Then
+                    state = True
+                End If
             End If
+
             Return state
         Catch ex As Exception
             LOGGER.Error(ex)