Assume that you join an audio or video (A/V) conference call that has at least three attendees by using Microsoft Lync for Mac 2011. One of the attendees drops out of the conference. In this situation, all Lync for Mac 2011 clients in the conference crash.
Note This issue only occurs in version 14.0.5 of Lync for Mac 2011 or a later version.
To resolve this issue, install the following cumulative update:
2909662 Description of the Microsoft Lync for Mac 2011 14.0.7 update