Unknown Error 0x0

Chris B 0 Reputation points
2026-07-29T14:23:22.38+00:00

I have a genuine Office Home & Business 2019 for Mac licence attached to my Microsoft account (added April 19, 2022). I am running Office 16.78.3. Activation fails with “Unknown Error 0x0”. The licence appears correctly under Services & Subscriptions. Please check the activation record for my licence and refresh or rebind it if necessary.

Microsoft 365 and Office | Install, redeem, activate | For home | MacOS
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  1. Gérard Oomens 129.2K Reputation points Volunteer Moderator
    2026-07-29T17:41:40.5966667+00:00

    Have a look at:

    https://support.microsoft.com/en-us/office/lifecycle/officeinstall/update-m365-office-macos-ios

    ....

    Office 2019 for Mac reached end of support on October 10, 2023, and no longer receives updates. Because Office 2019 cannot be updated to the required version, this issue cannot be resolved by updating or reinstalling Office 2019 for Mac. For more info, go to End of support for Office 2019 for Mac.

    .....

    https://support.microsoft.com/en-us/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos

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