Assume that you deploy Microsoft Lync Server 2010 Mobility Service in a Lync Server 2010 environment. When Mobility Service encounters an unhandled exception, a user cannot sign in by using a mobile device. Additionally, the following event is logged in the Application log on the server:
This issue occurs because Mobility Service does not correctly process the unhandled exception. This causes a deadlock in the service.
To work around this issue, recycle the W3wp.exe process when the issue occurs, and then users can sign in.