If you're experiencing an issue with logging into Microsoft Office on your Mac, you can use the license removal tool which will usually resolve most login issue. This will completely remove all licenses for Microsoft 365 for Mac.
This tool can also help if you've subscribed to Microsoft 365 but previously had a one-time purchase of Microsoft 365 for Mac on your computer, and aren't seeing certain features.
1. Download the license removal tool.
2. Open the .pkg file from your Mac's Downloads folder.
3. Select Continue and follow the prompts in the setup wizard.
4. When you're ready to complete the license removal, select Install. You may need to enter your Mac's local admin account password.
After the tool successfully removes licenses, select Close.
5. Now open any Office app and sign in to activate with the email account associated with your Microsoft 365 for Mac license. If you're troubleshooting an issue, you may need to reinstall office before signing in.
After you've successfully activated, restart your computer.
6. Uninstall the License Removal Tool by dragging the Microsoft_Office_License_Removal file from Finder > Downloads to Trash.