"LocalEndpointAllocationFailed" error is logged and Lync for Mac client becomes unresponsive randomly

Consider one of the following scenarios in Microsoft Lync for Mac 2011:

• You click the "Join Meeting" link in a meeting invitation in the Microsoft Outlook calendar.
• You send or receive an invitation for an audio or video call.

In this scenario, the client becomes unresponsive to user input, the Spinning Wait Cursor may be displayed, and the program freezes. 

Note These symptoms most likely occur after you have made many calls and joined many meeting by using Lync for Mac 2011.

Additionally, the following error message is logged in the client logs: