Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
This error is being reported with the Office apps on a Mac at the moment, follow these steps, step 3 is important.
1
Use the steps provided on this link to remove the Office licence from your Mac:
2
Uninstall the Office apps using the steps provided on this link:
https://support.microsoft.com/en-au/office/lifecycle/officeinstall/uninstall-office-for-mac
3
Then go to this link and scroll down to find all the installers for all Office versions and download the installer released on October 6th (Version 2609), then use that to install Office, that should work correctly.
https://learn.microsoft.com/en-us/officeupdates/update-history-microsoft365-apps-by-date