Cause
This issue occurs because the correct connection for a specified destination address and port can't be found when audio or video is being established while you join a meeting by using Microsoft Lync 2013 (Skype for Business).
Resolution
To fix this issue, install the March 8, 2016, update (KB3114831) for Lync 2013 (Skype for Business).Note Lync 2013 was upgraded to Skype for Business in April 2015.
