MS office 2021 suddenly requiring me to subscribe to 365 in order to save documents (I have a license and have always used offline)

Question

I have microsoft office 2021. In the "about" section the license shows up as "License: Office Home & Student 2021". It has always worked fine until a couple days ago when I stopped being able to save or edit any documents and am prompted instead to sign up for MS 365. I think this started around the same time I upgraded to Tahoe on my mac laptop. How do I fix this issue? I am using the same laptop as before, nothing has changed (except upgrade to operating system).

Answer 1

Hi,

Your Office 2021 license is still valid. The issue is likely related to the macOS upgrade and Office entering reduced functionality mode.

Since you are using macOS Tahoe, open Word or Excel, go to Help > Check for Updates, select Update or Update All in Microsoft AutoUpdate, and then restart the Office app.

If you still cannot edit or save, quit the app completely, reopen it, then sign out and sign back in with the Microsoft account linked to your Office 2021 license.

Answer 2

This usually means Office is no longer recognizing the installed license correctly and has dropped into reduced functionality mode, where files can be opened and printed but not edited or saved.

For a Mac with a one-time Office 2021 license, use this path:

1. In Word, go to Word > About Word.
   • Confirm it still shows Office Home & Student 2021.
2. In the same area, use More Info and then Refresh License if that option appears.
   • This can reconnect the installed apps with the existing license.
3. Check that the license is attached to the correct Microsoft account.
   • Sign in to https://account.microsoft.com/services.
   • Verify the Office 2021 purchase is listed there.
   • If it is listed, use that same account when Office asks to sign in.
4. If Office still behaves like Microsoft 365, remove old Mac license data and reactivate.
   • Microsoft provides a license removal tool for Mac that completely removes Office license files.
   • Important: have the correct account and password available before doing this, because Office must be reactivated afterward.
5. Reinstall Office from the Microsoft account Subscriptions/Services page if needed.
   • This helps ensure the installed copy matches the one-time purchase license instead of using the wrong activation state.
6. If the problem started after the macOS upgrade, update macOS first and then update Office apps to the latest supported versions.
   • Microsoft notes that on macOS, updating the OS first and then updating Office resolves reduced functionality issues caused by unsupported app/OS combinations.
7. If there are multiple Office copies installed, remove the extra copy.
   • Multiple installs can cause activation conflicts.

Important:

• If Office is not connected to the internet for long periods, Microsoft 365 apps can enter reduced functionality mode after 39 days, but that behavior applies to Microsoft 365 subscription activation. Since this installation shows Office Home & Student 2021, the more likely issue is license recognition after the macOS change.
• Removing license files is safe for the purchase itself, but it does clear local activation data. Reactivation is required afterward.

If the reinstall path is needed, reinstall only from the Microsoft account page where the Office 2021 purchase appears.

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References:

• How to remove Office license files on a Mac
• Unlicensed Product and activation errors in Office
• What to try if you can't install or activate Office for Mac
• Update Microsoft 365 or Office on your macOS or iOS device
• Microsoft Office stopped letting me edit. Requires Office 365 to edit - Microsoft Q&A