Saving documents in Office 365 suddenly stopped working

Reset the cached Office licenses on the Mac, then reactivate Word and Excel with the Microsoft account that owns the active subscription.

1. Verify the subscription account

Before removing anything, confirm that the required credentials and license are available:

1. Sign in at Microsoft account Services.
2. Confirm that the Microsoft 365 subscription is listed and active.
3. Note the exact account used. The presence of free Office web apps alone does not prove that the account has a Microsoft 365 subscription. ^1^

If this is a work or school subscription and no license appears, contact the organization’s Microsoft 365 administrator to verify that a desktop-app license is assigned.

2. Remove the cached Mac licenses

Since updating Office and Refresh License have already failed, do not repeat them.

Important: This removes all Office licenses cached on this Mac. Ensure the correct account credentials are available first.

1. Quit Word, Excel, and every other Office application.
2. Download Microsoft’s official Office License Removal Tool from the Microsoft Support procedure. ^2^
3. Open the downloaded .pkg, select Continue, and follow the wizard.
4. Select Install when prompted; enter the Mac administrator password if required.
5. When license removal succeeds, select Close.
6. Open Word and sign in using the exact account verified in step 1.
7. If asked to choose between a one-time-purchase license and Microsoft 365, choose Microsoft 365 for Mac.
8. After activation succeeds, restart the Mac.
9. Open a new Word or Excel document and save it to the local folder.

Only run a package downloaded directly through the official Microsoft Support page. If macOS reports an unidentified or unverifiable developer, do not bypass the warning; download the tool again from Microsoft Support or contact Microsoft Support.

3. If activation still fails

Reinstall Office only after the license reset:

1. Uninstall the existing Office applications.
2. Return to Microsoft account Services using the licensed account.
3. Select Install for the active Microsoft 365 subscription.
4. Run the installer, open Word, and sign in to activate.

Microsoft’s Mac license-removal guidance notes that reinstalling Office can be necessary before signing in again when troubleshooting activation. ^2^

If activation still fails, record the complete activation message and any error code, then check Microsoft’s Mac activation page for the matching error or any current issue. ^1^

References

1. What to try if you can't install or activate Office for Mac
2. How to remove Office license files on a Mac | Microsoft Support