Error 0x0 when trying to activate Office products

Alisha Musicant 0 Reputation points
2026-10-04T17:49:53.72+00:00

My Mac0S has been updated to Tahoe 26.5. I keep getting error 0x0 when I try to activate Office products. I've already run through the steps of trying to update in the app store (Office products don't appear there and I think they've already been updated). I've tried closing all the apps and reopening them. Still having this problem. Can you help?

Microsoft 365 and Office | Install, redeem, activate | Other | MacOS
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  1. EmilyS726 270.5K Reputation points Independent Advisor
    2026-10-04T18:22:50.9766667+00:00

    Hello, 26.5 is not the latest version for Tahoe. Please make sure your OS is up to date first. Latest Tahoe should be 26.7.1

    That alone might help.

    If not,

    Follow the instructions here for complete uninstall of Office product.

    https://support.microsoft.com/office/office-for-mac/troubleshoot-office-for-mac-issues-by-completely-uninstalling-before-you-reinstall?apid=ets

    Then reinstall this way:

    If you signed up via Apple App Store, then download and install from the App Store.

    If you signed up via Microsoft directly, please go to https://www.office.com

    Sign into the Microsoft account you used for the subscription. Click on the 9-dot icon on the upper left > More apps.

    Then on the upper right, click on "Install apps". This will now download the installer file. Once downloaded, click on the file to install. It will install the Desktop version of the apps for you then.

    https://support.microsoft.com/office/download-install-or-reinstall-microsoft-365-or-office-2024-on-a-pc-or-mac-4414eaaf-0478-48be-9c42-23adc4716658?apid=ets

    If it still doesn't work, download the updater https://support.microsoft.com/office/office-for-mac/troubleshoot-microsoft-autoupdate-in-microsoft-365-and-office-for-mac?apid=ets

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  2. AI answer

    2026-10-04T17:50:07.5033333+00:00

    For error 0x0 on Office for Mac, the supported fix is to make sure Office is updated through the correct update channel and then re-check activation.

    1. Confirm macOS version Office’s published fix for this issue requires macOS 12 or later. macOS Tahoe 26.5 meets that requirement.
    2. Update Office from Microsoft AutoUpdate Since the apps do not appear in the App Store, they were likely installed from Microsoft rather than the App Store.
      • Close all Office apps.
      • Open Finder > Applications > Microsoft AutoUpdate.
      • If Microsoft AutoUpdate is not there, check: /Library/Application Support/Microsoft/MAU2.0/
      • Install all available updates with Update All.
      • After updates finish, reopen an Office app and test activation.
    3. Make sure the correct account is being used A No license found / activation problem can happen if Office is signed in with the wrong Microsoft account.
      • Sign out of Office.
      • Sign back in with the account that owns the Microsoft 365 subscription or Office purchase.
      • If needed, choose Sign in with another account.
      • Verify the license on https://account.microsoft.com/services.
    4. Reset Office credentials on the Mac If activation still fails:
      • Open Spotlight.
      • Search for and open Keychain.
      • Search for Office.
      • Delete the data license file.
      • Then run the Microsoft 365 Activation troubleshooter: https://aka.ms/SaRA-OfficeActivation-sarahome
    5. If Office was activated with the wrong license If there are multiple licenses on the account, or there was a one-time Office purchase before Microsoft 365, remove the Office license files on the Mac and reactivate using the correct license.
    6. If the install source does not match the purchase source If Office was originally obtained from Microsoft, keep updating and reinstalling from Microsoft. If it was obtained from the App Store, use the App Store version. A mismatch can keep activation from completing.

    If the issue is specifically Unknown Error 0x0 / License not found, Microsoft lists it as a known issue resolved by Office updates, so Microsoft AutoUpdate is the primary fix path when App Store updates are not applicable.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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