All Word Files Became Read-Only. License Not Valid

You do not need a Microsoft 365 subscription to keep using your one-time-purchase Office 2021 license; if this started after the October 22 update, replace Office 16.114.1 with the October 6 build and reactivate Office 2021.

Check whether the affected build is installed

1. Open Word → About Microsoft Word.
2. Note both:
   • Version: if it is 16.114.1 (26102031), use the rollback below.
   • License: it should identify Office 2021, not Microsoft 365.

Microsoft’s update history confirms that 16.114.1 was released October 22, while the October 6 build is 16.113.4. ^1^

If Word is version 16.114.1

Recent matching reports—Office 2021 for Mac suddenly rejecting its perpetual license and entering read-only mode—were resolved by removing 16.114.1 and installing an earlier build. One accepted answer uses 16.114; another moderator-recommended answer uses the October 6 build, with users confirming that editing returned after activation. ^2^ ^3^

1. Back up any local Outlook data and Office templates you need.
2. Quit every Office application.
3. Uninstall the current Office applications.
4. Download and install the October 6, 2026 version 16.113.4 (26100421) from Microsoft’s Office for Mac update-history page. ^1^
5. Open Word and select Activate in the license banner.
6. Sign in with the Microsoft account used to purchase or redeem Office 2021.
7. Confirm Word → About Microsoft Word now shows Office 2021 and test creating, editing, and saving a document.
8. Temporarily open Help → Check for Updates and turn off automatic updates so that 16.114.1 is not immediately reinstalled.

Rolling back and disabling updates is a temporary workaround and leaves you without later fixes, so monitor Microsoft’s recent activation-issues page before updating again. Microsoft currently lists a resolved July “License Not Found” issue, but the supplied official status page does not document the newer October 16.114.1 regression as fixed. ^4^

If you are not running 16.114.1

First ensure the Mac runs macOS 12 or later, then open Help → Check for Updates → Update All. Microsoft documents reduced-functionality mode—Office opens files but cannot edit or save—for unsupported Mac/Office combinations and says to update macOS first and Office second. ^5^

If updating does not restore activation:

1. Verify that Office 2021 appears under Products you’ve purchased on the Microsoft account’s Services page.
2. Quit all Office applications.
3. Run Microsoft’s Office license removal tool. This removes Office licenses from the Mac, so have the purchasing account and password available first.
4. Reopen Word, sign in with that account, select the Office 2021 license if prompted, and restart the Mac after activation. ^6^

If Word came from the Mac App Store, replace it with the installer associated with the Office 2021 purchase. Mac App Store Word requires a Microsoft 365 subscription; perpetual licensing is not supported for those App Store applications. ^7^

What end of support means

Office 2021 support ended October 13, 2026. That ends technical support, bug fixes, security fixes, and future Office 2021 updates; it does not automatically convert a perpetual license into a subscription. Microsoft says the applications may continue working, although continued use carries security and compatibility risks. ^8^

Therefore:

• No, Microsoft 365 is not required merely to preserve the Office 2021 license.
• No permanent fix is currently documented for the October regression in the official incident list.
• The supported long-term choices are a newer perpetual Office release or Microsoft 365; the rollback is an interim recovery method for the affected build.

References

1. Update history for Office for Mac
2. Office Home & Student 2021 (one-time purchase) will not activate on Mac - "No License Found" - Microsoft Q&A
3. Office 2021 perpetual version not working on Mac after Microsoft Home ...
4. Fixes or workarounds for recent Office installation or activation issues | Microsoft Support
5. Update Microsoft 365 or Office on your macOS or iOS device
6. How to remove Office license files on a Mac | Microsoft Support
7. Deploy Office for Mac from the Mac App Store
8. End of support for Office 2021 | Microsoft Support