I just upgraded my Macbook Pro to OS 10.13 High Sierra yesterday. After upgrading, I could not run Outlook 2016 any more. I got this message:
You can’t use this version of the application “Microsoft Outlook” with this version of macOS.
You have “Microsoft Outlook” 15.25
Fortunately, the solution is easy. Just run Microsoft AutoUpdate and update the Outlook to 15.35 or later version.