This issue occurs because an existing peer-to-peer application sharing session is not cleaned up when you escalate it to a conference by using content sharing, such as a whiteboard or a PowerPoint presentation.
Note The memory leak may be up to 100 MB.
When this issue occurs, you may encounter one of the following issues:
Microsoft Lync 2013 crashes.
You cannot create an application sharing session in Lync 2013, such as a desktop sharing session or a PowerPoint sharing session.
You cannot join or create an online meeting in Lync 2013.
This issue occurs because an existing peer-to-peer application sharing session is not cleaned up when you share another application.
To resolve this issue, install the following update:
2899507 November 11, 2014 update for Lync 2013 (KB2899507)