Topic Last Modified: 2011-03-02

You can use the Microsoft Lync 2010 log file, Communicator-uccapi-0.uccapilog, to troubleshoot client issues.

The files are located under <Drive>:\Users\%User%\Tracing

Issue: A SIP-enabled contact object cannot sign in

If a SIP-enabled contact object cannot sign in, take the following steps to resolve the issue:

• Check the client logs to see if a 401 error appears. If so, there may be an authentication problem.
  
  
  • Check the contact object with LDP.exe, and ensure all SIP attributes are populated and msRTCSIP-OriginatorSid is set for all contact objects. Otherwise, authentication will fail.
    
    
  • If the contact is not created properly, check the server logs of the identity life cycle manager.
    
    
  • If needed, set the Lcssync logging level to 3. For details, see Install the Lync Server Sync Tool. Resynchronize the contact to confirm why the contact object is not being created.
    
    
  • Verify that credentials (user name and password) from the original user forest are used. If the central forest is in the Contoso domain, and the user object is replicated from the Northwind Traders domain to Contoso as a contact object, Northwind Traders credentials must be used to sign in to the domain.
    
    
  • Check the cross-forest trust relationship. The central forest must trust incoming credentials from the user forest.
    
    
• If client receives a 404 error, there is a replication issue.
  
  
  • Verify that the contact object is properly SIP-enabled and that it exists in the Lync Server 2010 database.
    
    
  • Use Dbanalyze.exe, which is available in the Lync Server 2010 Resource Kit, to get the user report for this particular user. Ensure that the user exists in the database.
    
    
  • Check the Lync Server logs for real-time communications (RTC) User Replicator errors or warnings.