We have been experiencing the same thing for a few months now. We've narrowed down to being the Unified Communications DLL (UC.DLL) which crashes when Outlook is open, causing Skype for Business 2016 to crash as well. We are on 4.7 client.
Majority of our users if they fire up Skype for Business before they open Outlook, Skype seems to be more stable, but that's not the case with 100% of our users.
Can anyone offer some insight or maybe someone that has experienced this issue before can point us in the right direction?