Assume that you have branch sites in the topology of a Microsoft Lync Server 2010 environment. You deploy Survivable Branch Appliances (SBA) or Survivable Branch Servers (SBS) to the environment. In this situation, the Registrar service (RTCSrv.exe) may crash on a Lync Server 2010 server in the environment.
This issue occurs because the Registrar service encounters an access violation when the Registrar service tries to register a branch user whose home server is set to a branch site.
To resolve this issue, install the following cumulative update:
2791381 Description of the cumulative update for Lync Server 2010: March 2013
For more information about how to deploy a Survivable Branch Appliance or Survivable Branch Server, go to the following Microsoft website: