Trying to active Office 2019 on Mac: An unknown error has occurred. The error code is: 0x0

Question

I had to "force quit" Excel and then it ask for activation. I did as usual but this error shows: An unknown error has occurred. The error code is: 0x0. I did run the official MS license removal tool and it did not help.

Answer 1

This is unacceptable. I have paid for the software!

Answer 2

Hello,

Unfortunately, the license removal tool will not resolve this particular issue.

Starting July 13, 2026, Office 2019 for Mac entered reduced functionality mode because its licensing certificate can no longer be updated. Office may still open documents, but it can no longer activate for editing, saving, or creating files. The 0x0 error is part of that activation failure.

Force-quitting Excel did not cause the problem. It likely caused Excel to check the license again, which exposed the certificate issue.

Microsoft confirms that Office 2019 for Mac cannot be updated to the required version, and reinstalling Office 2019 will not resolve it.

The available options are:

1. Use Word, Excel, and PowerPoint online for free through Microsoft 365 for the web.
2. Purchase a supported version such as Office Home 2024.
3. Subscribe to Microsoft 365.

Your existing documents are not deleted or damaged, but Office 2019 for Mac can no longer be restored to full editing mode through activation troubleshooting.

https://support.microsoft.com/en-us/office/update-microsoft-365-or-office-on-your-macos-or-ios-device-f418ae5d-bb5f-4078-b3d9-9340f5dd084e