Office 365 goes to Read Only Mode
Office sometimes loses its license and tells a user it's in Read Only mode. To have Office reactivate again follow the steps below.
Open the users keychain folder in Finder at ~/Library/Keychains, ie /Users/uniqname/Library/Keychains
Look for directories that have a UUID-type name, ie ‘962ACF28-6B33-4ACC-9997-4F8096C8856A’ and delete it. (This is just an example, delete all directories that have a similar name)
Reboot the computer.
Login and open Word or Excel.
On the New Document screen in the bottom left, click Activate.
Login with your Umich email address to reactivate Office.
If this does not work, please try the following:
Open Applications → Service Provider Support and run the “Office 365 License Removal Tool” task. That usually will resolve the problem if removing the UUID-type named directory does not.
If even that does not work, run the “Microsoft Office Uninstaller” in Service Provider Support and then reinstall Office from Managed Software Center as it may be possible an automatic update of an Office application did not complete properly and a brute-force reinstall would resolve that.
To check how many 365 Office activations a user currently has you can login here:
https://myaccount.microsoft.com/device-list
Sponsored accounts with no other affiliations are not licensed to use Office on the mac.
They can use the online version at Office.com