Article ID: 2884055 - View products that this article applies to.
Consider the following scenario:
Note After this issue occurs, you can’t make or receive calls until you restart Lync for Mac 2011 and then sign in again.
Cannot connect to the call
To resolve this issue, install the following cumulative update:
(http://support.microsoft.com/kb/2884053/ )Description of the Microsoft Lync for Mac 2011 14.0.5 hotfix