Microsoft Office and Student 2019 not working my new MacBook Pro

Microsoft Office and Student 2019 was bought with and only installed on my new MacBook Pro in Oct '19. All went well until early in 2020 then its failed. Repeated clearing of keychain etc WILL NOT RUN IT. REPEATED REINSTALLATION OF IT will NOT RUN IT.

Today its first sigh of life was a Microsoft Word Update which installed. However: the package does not open / run.

The issue is still in Microsoft court to sort I suggest!

[Re-Titled by Moderator]