Issue: Unable to see Whiteboard and PowerPoint present option on Lync meeting.
If you check event log on Lync Front End server then you will see error event ID: 41027.
Event Error shows "The content file store is full or unavailable, and no more data can be written to it." However file store has adequate free space available.
This was known issue if you are using DFS as file store. Workaround was restart front end server.
However recently Microsoft released Cumulative Updates on May 1st 2015 and this CU has DFS bug fix.
I have installed May 1st 2015 cumulative updates on Lync Server 2013 (Front End, Persistent Chat and Edge Server).
DFS issue appears to be resolved.
Before CU I was seeing error Event ID: 41027.
After CU update not seeing this event ID: 41027 on Front End Server.
Latest Cumulative Updates you can download.
You can refer How to install CU on Lync article.