Office 365 activation generates Error 0x0

John Chmaj 5 Reputation points
2026-07-14T17:18:18.64+00:00

Trying to get Excel to edit and save documents now. Tried activating using my existing Office 365 account, get a message "Unknown Error" an unknown error has occurred. The error code is: 0x0. Activation screen freezes.

Microsoft 365 and Office | Install, redeem, activate | Other | MacOS

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  1. DYARI BARHAM 37,076 Reputation points Independent Advisor
    2026-07-14T18:14:20.86+00:00

    Hi ,

    I'm Dyari. Thanks for reaching out.

    Please go to Control Panel > Credential Manager > Look for any entries related to MicrosoftOffice, OneDrive, or ADAL and click Remove.

    If it does not help, go to Control Panel > Programs and Features > Right-click your Microsoft Office or Microsoft 365 installation > Change > Quick Repair.

    Go to Settings > Accounts > Access work or school. Disconnect any accounts that aren't associated with your active subscription.

    After that, open Word > Sign in if it asks > See if the issue is fixed.

    If it is not, are you using Windows or macOS? Did you previously have a different version installed on this computer?

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    1 person found this answer helpful.
  2. Bryan Hermsen 0 Reputation points
    2026-08-09T23:02:57.9566667+00:00

    This worked for me on a MacBook Air: https://support.microsoft.com/en-us/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos.

    In my case, it was the second set of instructions, "installed individual Office apps from the App Store."

    If you installed Microsoft 365 or Office from microsoft.com, follow these steps:

    1. Ensure that you are running at least macOS version 12 or higher.
    2. Close all Office applications.
    3. Open the Microsoft AutoUpdate (MAU) from Finder > Applications > Microsoft AutoUpdate. Note If you don’t see MAU, check /Library/Application Support/Microsoft/MAU2.0/
    4. If you want to learn about the details of each update before installing, select the arrow next to the Update button and review the apps, versions and installation date. Then select Update All or Update next to individual apps.
    5. After the updates are complete, launch the Office application again to test.

    If you installed individual Office apps from the App Store (less likely) follow these steps:

    1. Ensure that you are running at least macOS version 12 or higher.
    2. Close all Office applications.
    3. Open the App Store.
    4. Select Updates from the sidebar
    5. Look for:
      • Microsoft Word
      • Microsoft Excel
      • Microsoft PowerPoint
      • Microsoft Outlook
      • Microsoft OneNote
    6. Select Update next to each app or Update All.
    7. After the updates are complete, launch the Office application again to test.

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