Recently i have suffered from a real pain in the ar5e issue with Lync for Mac 14.3.3
Backtracking to February when 14.3.3 arrived as GA, i noticed that my Lync for mac client became really unstable with random crashes and general instability of the client. As this only become present with the 14.3.3 update, i downgraded back to the 14.1.1 build which brought the client back to a workable/normal state. At the time of going to 14.3.3 i had also been running a few Microsoft UC TAP/beta programs and i was thinking that it could be these clients causing the issues and instability i was seeing.
So, i decided that it was time for a new OSX rebuild of my machine and to get a good clean image to build upon. Following the OSX installation, i loaded Office 2016 for mac, and set my profile correctly before installing Lync for Mac 14.3.3 **without any TAP/Beta installations!.. AGAIN i saw the same random instability issues including the spinning beach ball cursor (not responding) from the Lync for Mac client. Again i ran with this setup for a few days, but then decided that the client was physically unworkable and was left again with no choice but to downgraded back to 14.1.1 which like before worked flawlessly.
This now led me to believe (in error) that it was either el-capitan OR office 2016 for Mac. ? so i set about investigating both with more several rebuilds… On builds i did notice that applying my profile before Office 2016 meant the issue was still seen.??? arghh.
One common dominator though was on a fresh rebuild of OSX THEN the installation of Lync for Mac 14.3.3 without Profile and Office 2016 would work perfectly and that the issue would only arrive back when i installed either Office 2016 or on the configuration of my profile (dock, power setting, screen saver etc).
Anyhow after a far to long and drawn out process of elimination, i finally cracked the riddle of the problem, and this being……
There is a bug in Lync for Mac 14.3.3 which is nothing to do with El-Capitan OR Office 2016 but was in fact the use of a OSX profile picture greater in mb size of 5mb.! IF you changed your picture to > greater than 5mb you will start to see instability of the Lync for mac client 14.3.3. (this didn’t happen in 14.1.1).
Simple resolution was to downgrade the profile picture to less than <5mb and the client became workable using 14.3.3 **note: this has been raised with Microsoft.