Office 2021 for Mac shows "Not Activated" after macOS Tahoe update — all official fixes tried, cannot reach support

Della Peretti 0 Reputation points
2026-08-31T15:28:31.2133333+00:00

I have a one-time-purchase license for Office Home & Business 2021 for Mac (not a subscription). Since updating to macOS Tahoe 26.5.1, Word/Excel/PowerPoint show "License: Not Activated" in About Word, and the apps are in reduced functionality mode — I can view/print but not create, edit, or save. I'm repeatedly prompted to subscribe to Microsoft 365 instead of using my existing license.

I'm aware of the published bulletin "[RESOLVED] Unknown Error 0x0 or License not found error in Microsoft 365 or Office running on macOS" (fixed via AutoUpdate, published July 15, 2026). I applied that fix and it did NOT resolve my issue, so this appears to be an account-specific case, not the general bug.

What I've already tried, none of which worked:

  • Confirmed the Office 2021 license is still listed under Services & Subscriptions on my Microsoft account, and I'm signed into Word with that same account
  • Fully updated Office via Microsoft AutoUpdate
  • Removed old license files with Microsoft's official license removal tool, then reinstalled from account.microsoft.com/services
  • Booted into Safe Mode and tested — activation prompt still appeared
  • Called Microsoft customer service (1-800-642-7676) — the call plays a recording pointing to the website and disconnects, no agent reachable
  • Tried the official support.microsoft.com chat flow multiple times — routed back to the same self-help articles, never reaches a live agent option
  • Tried in-app Help > Contact Support in Word — returns "This product is no longer supported," no chat available

Screenshot attached showing "License: Not Activated" with my account (******@gmail.com) correctly signed in.

I'd like to keep using my purchased perpetual license rather than being pushed into a subscription. Given that none of the standard support channels are reachable, could a moderator or MVP here help escalate this, or point me to a channel that actually connects to someone who can check my account server-side?

Thank you.

Microsoft 365 and Office | Install, redeem, activate | For home | MacOS

2 answers

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  1. AI answer

    2026-08-31T15:28:53.5333333+00:00

    For a one-time Office 2021 for Mac license, the most likely causes in this scenario are:

    1. The wrong Office build is installed. Office apps downloaded from the Mac App Store require a Microsoft 365 subscription and are not compatible with one-time licenses such as Office 2021 Home & Business. If the Mac App Store build is installed, Office will show reduced functionality and prompt for Microsoft 365.
    2. Stale activation data is still blocking the perpetual license. Since updates, reinstall, and the license removal tool were already tried, the remaining supported checks are the account/build match and a full license reset path.

    Use this supported verification path:

    1. Confirm the installed apps are not the Mac App Store version. If Office was ever installed from the Mac App Store, uninstall that copy and use only the installer from the Microsoft account services page tied to the Office 2021 purchase.
    2. Verify the signed-in account is the licensed account. Sign out of Office, then sign back in with the same Microsoft account that shows the Office 2021 license under Services & Subscriptions.
    3. Reset activation credentials again from Keychain.
      • Open Spotlight.
      • Search for and open Keychain / Keychain Access.
      • Search for Office.
      • Delete the Office data license file.
    4. Run the official license removal tool again. Caution: this removes saved activation data, so the correct licensed account must be available for sign-in afterward. After the tool completes, open an Office app and sign in with the account associated with the Office 2021 for Mac license.
    5. If the issue persists, remove the identity cache entries listed by Microsoft, then restart and reactivate. In Keychain Access, delete:
      • Microsoft Office Identities Cache 3.
      • Microsoft Office Identities Settings 3.
      • Microsoft Office Ticket Cache.
      Then restart the Mac and open any Office app to reactivate.
    6. Make sure macOS is version 12 or higher and Office is fully updated. Microsoft’s resolved bulletin for License Not Found / Unknown Error 0x0 requires at least macOS 12 and current Office updates.

    What is supported from Microsoft for escalation:

    • For work or school accounts, Microsoft directs users to the organization’s tech support if the license was not set up by the administrator.
    • For consumer activation issues that still fail after the supported steps, the documented public path is Microsoft support contact and guided support.

    What is not supported by the available guidance:

    • No documented moderator, MVP, or public server-side escalation path is provided for account-level activation repair beyond the public support/contact flows.

    References:

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

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  2. EmilyS726 278.4K Reputation points Independent Advisor
    2026-08-31T16:08:37.92+00:00

    Hello

    Your Tahoe is not running the latest version. Can you update to 26.6.2? If so, that alone might address the issue. Try that first.

    If that still doesn't work, try this:

    First, see if you can update your Office apps. Open Word for example, click on the 'Help' tab >Check for Updates. Make sure you choose Update All when prompted. Let the process run through, can take a bit time. See if that works.

    Otherwise, use the Update method in this article: https://support.microsoft.com/support/known-issues/unknown-error-0x0-license-not-found-error-microsoft365-macos?apid=ets

    If it still doesn't work, please uninstall the apps. Follow the instructions here for complete uninstall.

    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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