Unable to activate Microsoft 365

Pieter van Straten 10 Reputation points
2026-07-20T21:12:18.46+00:00

Unable to activate Microsoft 365

Just purchased Microsoft Office for Mac Big Sur; after installation I receive 'unknown error' when trying to activate.Screenshot 2026-07-20 at 23.10.17

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

Locked Question. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

1 answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. EmilyS726 272.9K Reputation points Independent Advisor
    2026-07-20T21:44:15.9266667+00:00

    Hello

    Any chance your Big Sur can support upgrading to at least macOS 12 or above?

    If your OS is above version 12 but below 14, your office products can be functional, but Microsoft no longer maintains or updates that version. In this scenario, you can install the older downgraded version and keep office working.

    However, if your macOS is below 12, Office products will now enter reduced functionality mode. In other words, the OS is too old to receive the licensing update the Office now requires. Sorry.

    This is an update that occured on July 13th and Microsoft shared it here: https://support.microsoft.com/office/update-microsoft-365-or-office-on-your-macos-or-ios-device-f418ae5d-bb5f-4078-b3d9-9340f5dd084e

    If your device cannot update its OS to at least 12, your options will be: Use the web version or an alternative like LibreOffice. And you want to cancel your subscriptions.

    Was this answer helpful?