Unknown Error. Error code is 0x0

Question

When trying to use Excel, I keep getting Unknown Error. Error code is 0x0.

Answer 1

Hi John,

The 0x0 error is widely reported with the Office apps on an Apple Mac device at the moment.

1

What version of Microsoft Office do you have, is that a subscription to Microsoft 365 or a standalone version of Office like Office 2019, 2021 or 2024.

2

At the top left of your Mac desktop, click the Apple icon and select 'About this Mac', what version of MacOS is installed on your computer?

Answer 2

For Microsoft 365, Office 2021, or Office 2024 on Mac, resolve error 0x0 by updating Office through its original installation channel; Office 2019 or earlier requires a supported replacement rather than activation repair.

1. Check the installed versions

In Excel, select Excel > About Microsoft Excel and note:

• The edition: Microsoft 365, Office 2024/2021, or Office 2019
• The Excel version
• Your macOS version from Apple menu > About This Mac
• Whether Office came from Microsoft or the Mac App Store

These details determine which branch applies.

2. Microsoft 365, Office 2021, or Office 2024

Microsoft marks this particular macOS activation issue as resolved through an Office update. The documented procedure requires macOS 12 or later.^1^

Office installed from Microsoft:

1. Quit Excel and every other Office application.
2. Open Finder > Applications > Microsoft AutoUpdate.
3. If it is not there, in Finder select Go > Go to Folder, enter: /Library/Application Support/Microsoft/MAU2.0/
4. Open Microsoft AutoUpdate and select Update All.
5. When updating finishes, reopen Excel and sign in with the account holding the Office license.

Office installed as individual Mac App Store apps:

1. Quit all Office applications.
2. Open App Store > Updates.
3. Update Excel and the other installed Microsoft apps, or select Update All.
4. Reopen Excel and test activation.

Do not mix installation channels: App Store installations should be updated through the App Store; Microsoft installations should use Microsoft AutoUpdate.^1^

3. Older macOS versions or incompatible Office builds

Do not reinstall the newest Office package until the macOS version is known.

• macOS Monterey 12: If Microsoft AutoUpdate says that an upgrade is required or cannot install the current build, uninstall the incompatible Office build and install the final Monterey-compatible release from Microsoft’s Office for Mac update history. Q&A reports differ between versions 16.88 and 16.89.1, so use the compatibility table rather than selecting a package solely from a forum post.^2^^3^
• macOS Ventura 13: If the Mac cannot be upgraded and the current Office build is incompatible, moderator guidance identifies Office 16.101 as the final Ventura release. Uninstall the incompatible build, install that compatible build, and activate again.^4^
• Earlier than macOS 12: The required licensing update is unavailable. Use Microsoft 365 for the web, move Office to a supported Mac, or upgrade macOS where the hardware permits.^4^

Uninstalling Office removes the applications; back up any locally stored templates or customizations first. It does not require deleting normal workbook files.

4. If Office is updated but activation still fails

Reset only Office’s licensing credential:

1. Open Spotlight, search for Keychain Access, and open it.
2. Search for Office.
3. Delete only the Office data-license file specified by Microsoft’s activation procedure—do not delete unrelated passwords or credentials.
4. Run Microsoft’s Microsoft 365 Activation troubleshooter.
5. Reopen Excel and sign in with the licensed Microsoft account.

Microsoft documents this credential reset for Office for Mac activation failures.^5^

Office 2019 or earlier

As of the July 2026 licensing change, Office 2019 for Mac cannot restore editing activation through updating, reinstalling, or credential resets. The available paths are:

• Use Microsoft 365 for the web.
• Subscribe to Microsoft 365.
• Purchase a supported perpetual version such as Office Home 2024.^4^

If a supported edition still shows 0x0 after the correct compatible update and licensing reset, contact Microsoft Support and provide the macOS version, Excel version, Office edition, installation channel, and subscription account type.

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References

1. Unknown Error 0x0 or License not found error in Microsoft 365 or Office running on macOS | Microsoft Support
2. Excel for Mac cannot activate Microsoft 365 subscription (Unknown Error 0x0) while other Office apps work - Microsoft Q&A
3. I can no longer log in to my Microsoft 365 account and i get the error code 0x0 on my MAC. I've upgraded my MAC OS to 12.7.6 - Microsoft Q&A
4. 0x0 Error After Mac Update July 14th, 2026 - Microsoft Q&A
5. What to try if you can't install or activate Office for Mac