Most likely, Office has been moved to a new location. Open keychain (cmd+space, type in keychain, hit enter). Here’s how to do it: Open the Keychain Access app on your Mac From the menu bar, select “Keychain Access” Select “Keychain First Aid” from the drop down menu
That made sense 20 years ago, but IMO, not today. Macos wants to make changes macos wants to use the system keychain I have some steps I'd like you to try.
