I have run into this issue few times that fresh installed CRM 2016 Outlook addin (downloaded directly from the CRM) are grayed out in Outlook 2013. I have uninstalled other Outlook add-ins to make sure no interference; re-installed CRM Outlook add-in; also used CRM diagnostic to enable add-in without luck. The only solution I have is to re-create user's Windows profile and I prefer not to go that route every time we ran into this issue.
Please advise. Thanks
Calvin