diff --git a/app/DD_PM_WINDREAM/ClassPMWindream.vb b/app/DD_PM_WINDREAM/ClassPMWindream.vb
index 45c6458..aac8803 100644
--- a/app/DD_PM_WINDREAM/ClassPMWindream.vb
+++ b/app/DD_PM_WINDREAM/ClassPMWindream.vb
@@ -430,7 +430,7 @@ Public Class ClassPMWindream
         Try
             If Indexname IsNot Nothing Then
                 If Not oDocument.aLocked Then
-                    oDocument.lock()
+                    oDocument.LockFor(WMObjectEditModeIndexEdit)
                     Dim i As Integer = 0
 
                     ' das entsprechende Attribut aus windream auslesen