Problems with Mendeley Word Plugin for Mac Users
Mendeley Desktop does not currently support 64 bit versions of Word 2016. If you are using this version of Word, you may be unable to install, find, or use the plugin in Word.
This is something we are working on, but we do not have a timeframe for support at present. As soon as we know more, or have a timeframe for support, we will let you know
In the meantime, you should be able to copy and paste references from Mendeley Desktop directly into Word to form a bibliography, or if you are able to revert to a 32 bit version of Word 2016 from https://support.microsoft.com/en-us/kb/3179163, then this is supported by Mendeley, and should function as normal.