You see duplicate items in an external list in Outlook 2010 after the external list is upgraded


Consider the following scenario:
  • You have a server that is running Microsoft SharePoint Server 2010 with Enterprise Client Access License (CAL) enabled. 
  • You create an external list and then associate the list with an installed Business Connectivity Services (BCS) simple solution.
  • You associate the external list with an Outlook external content type.
  • You take the external list offline to Microsoft Outlook 2010.
  • On the instance of SharePoint Server 2010, you make a change to the external list that changes the list's version number. For example, the external list's version number changes from to
  • In Outlook 2010, you check for updates to the external list and then click Update Now to update the list.

    Update Now
  • When the update finishes, you click Close All to restart Outlook 2010.
In this scenario, the external list now has duplicate entries in Outlook 2010.


To work around this issue, uninstall the list, and then reinstall the external list in Outlook 2010.

Artikelnummer: 983015 – Letzte Überarbeitung: 26.08.2011 – Revision: 1