Mac Outlook 2016 Authentication Couldn’t be Completed Error Fixed

When I tried to open Outlook on my Macbook Pro, I noticed that the folders are not synced. I checked the account settings and there is a yellow dot by my account. I tried to delete the account and set it up again and I got this error message:

Authentication couldn’t be completed.

Tried re-install Outlook did not fix it. Finally found out how to fix this problem. Here are what I did:

  1. Quit Outlook.
  2. Open up Finder.
  3. Browse to ~/Library/Containers
  4. Find these two folders and move them to trash. (You might not have the profilemanager folder)
  5. Open Outlook and try add the account.