Hello!
Thanks for posting on the Microsoft Community, and we're sorry that you're experiencing this issue. We have identified the source of this problem and our engineering team is working on a fix. I'll post back once the update containing the fix is released.
Thanks,
Michelle V
Office Team
It's now November 2017. I'm also having this problem.
Here's the reply I got, when I sent in an actual ticket:
This is Cora Scott and I am the Engineer that has been assigned to your case (xxx).
Have you signed out and signed back into Office 2016 using your Office 365 credentials?
To sign out of your account, please click on
File > Office Account > User Information > Sign out.
Then close Outlook and restart your computer. After the restart, open Outlook and sign back in to update the licensing information.