You cannot log on to the Lync 2010 client or to the Office Communicator client when an additional authentication dialog box is displayed

Applies to: Lync 2010Microsoft Office Communicator 2007 R2

Symptoms

When you try to log on to either the Microsoft Lync 2010 client or to the Microsoft Office Communicator client for the first time, you can see the presence information for all contacts. However, when an additional authentication dialog box is displayed, you cannot log on to either the Lync 2010 client or the Communicator client. 

Note The additional authentication is required for Outlook integration.

Cause

This problem occurs if your mailbox has been moved from one server that is running Exchange Server to another Exchange server.

Resolution

To resolve this problem in Office Communicator 2007, follow these steps:  
  1. Click Start, click Run, type %USERPROFILE%\AppData\Local\Microsoft\Communicator\, and then click OK.
  2. Click the Galcontacts.db file.
  3. Press the DELETE key, and then click
    Yes.
  4. Completely close the Communicator client, and then log back on to it.

To resolve this problem in either Lync 2010 or Office Communicator 2007 R2, follow these steps:
  1. Click Start, click Run, type %userprofile%\Local Settings\Application Data\Microsoft\Communicator\sip_user@contoso.com, and then click
    OK.
  2. Click the Galcontacts.db file.
  3. Press the DELETE key, and then click
    Yes.
  4. Completely close the Lync or Office Communicator client, and then log back on to it.