I can't login to my subscription to Microsoft 365 on my Mac.

Run Microsoft’s Office License Removal Tool rather than deleting more Keychain entries; it removes all local Microsoft 365 for Mac license files so the apps can create a clean activation state.

Reset the Office license

You have already updated macOS, closed the apps, cleared Keychain entries, restarted, and verified the subscription online, so do not repeat those steps manually.

1. Make sure you know the email address and password attached to the active subscription. The removal process deletes licenses from this Mac, but it does not cancel or alter the subscription.
2. Download Microsoft’s license removal tool.
3. Open the downloaded .pkg file.
   • If macOS reports an unidentified developer, Control-click the file and select Open.
4. Select Continue, follow the prompts, and then select Install. Enter the Mac administrator password if requested.
5. When the tool reports that the licenses were removed, select Close.
6. Open Word first and select Sign in or Sign in with another account.
7. Enter the email address associated with the Microsoft 365 subscription.
   • If offered a choice between a one-time Office license and Microsoft 365, select Microsoft 365.
8. After activation succeeds, restart the Mac.
9. Remove the downloaded removal tool by dragging Microsoft_Office_License_Removal from Finder → Downloads to Trash.

These are Microsoft’s documented removal and reactivation steps.^1^

If “Something went wrong” remains

The wording alone does not identify a specific activation error. Check the pop-up carefully for an error code, particularly one beginning with 0x or a bracketed number.

• No code appears: Reinstall Office, but only after completing the license removal above. Microsoft documents reinstalling as the next conditional step when activation remains unsuccessful after license removal.^1^
• Code 0xD000000C appears: If the macOS login is a network account, sign out of macOS and activate Office from a local macOS user account. This code can occur when Office cannot write credentials to a read-only network-account Keychain.^2^
• Another code appears: Use the code-specific branch in Microsoft’s Office for Mac activation guide rather than repeating credential cleanup.^3^

If a clean license reset and reinstall both fail, contact Microsoft Support and provide:

• The exact error code or a screenshot of the complete message
• macOS version
• Office version from Word → About Microsoft Word
• Whether the Mac account is local, network-based, or workplace-managed
• Confirmation that browser sign-in works and the subscription is listed as active

References

1. How to remove Office license files on a Mac | Microsoft Support
2. Error 0xD000000C when activating Office for Mac | Microsoft Support
3. [Activation](https://support.microsoft.com/microsoft-365-activation-licensing/what-to-try-if-you-can-t-install-or-activate-office-for-mac)