Corporate error reporting (CER) is every time that you do one of the following in Microsoft Lync 2013 (Skype for Business):
You make or answer a PC-to-PC audio or video call.
You join an online meeting.
To fix this issue, install the December 8, 2015 security update (KB3114351) for Lync 2013 (Skype for Business).
Note Lync 2013 was upgraded to Skype for Business in April 2015.