Unable to sign into app

LeeB950 

I had a similar issue.

Error 1805 activating office 365 after updating to Monterey 12.5.1

I found that for my case, the issue was in relation to the Apple user profile and Office 365 licensing.

During my investigation, I was able to create a new profile and there was no problem activating Office 365. So I suspect, the issue also relates to to profile's KeyChain.

I did find a solution, which was to run the Microsoft License removal tool:

https://support.microsoft.com/en-us/office/how-to-remove-office-license-files-on-a-mac-b032c0f6-a431-4dad-83a9-6b727c03b193

After running the tool, I was able to activate all Office 365 application installed on the Mac normally.

Hope this helps anyone else with the same or similar issue.

Thanks,

Guy