Microsoft has replaced the November 2016 Cumulative Update with a newer release at December 13, 2016. It is a minor update which resolves an issue with contact search in Lync.
A search on mobile clients and Mac clients was returning no results at all with the first release of CU Update.
Knowledge base article which describes the issue: https://support.microsoft.com/en-us/kb/3212869
You will see an application log event on Lync Front End servers:
Event ID 20003
Source: LS UCWA
KB article for Lync Sever Cumulative Updates: https://support.microsoft.com/en-us/kb/2809243
