Can't login to Microsoftt apps after Mac Tahoe 26.2 update

Question

I updated my Mac to macOS 26.2 today. I am now unable to log in to any of my Microsoft Office apps. I have uninstalled and reinstalled them, signed out and quit all the apps, and I continue to receive an error message that reads "Another account from your organization is already signed in on this device. Try again with a different account," even though I am not signed in to any of the apps at all.

While I can sign in and access most of my documents online, any I created on my Mac are now read-only. How do I fix this? This is incredibly frustrating.

Answer 1

Hi Andrea M

Thank you for reaching out to Microsoft Q&A Forum and sharing your experience.

Based on your description, this behavior is commonly caused by stale or corrupted Microsoft sign‑in credentials left on the Mac after a system update. Even if no Office apps appear signed in, macOS may still be holding an older work or school account in the background, which triggers the error “Another account from your organization is already signed in on this device”. When this happens, Office apps may open local files in read‑only mode.

Since you have already reinstalled Office and signed out of all apps, please try the steps below to fully reset cached credentials on macOS.

• Quit all Microsoft Office apps completely.
• Open Spotlight (Command + Space), search for “Terminal” to run the following command and press Return:

defaults write com.microsoft.Word ResetOneAuthCreds -bool YES

For further information: Another account from your organization is already signed in on this computer

If the error continues, please use Microsoft’s official License Removal Tool for Mac, which removes leftover license files and activation data that standard reinstalls do not clear. This tool is recommended when Office continues to detect an old account that is no longer actively signed in. Once you are able to sign in successfully, please check whether your local files are no longer opening in read‑only mode.

Since this post is tagged "For education", kindly also confirm that you are signing in with a school account (not a personal Microsoft account) and that the account includes an active Microsoft 365 Apps license.

Please let me know how things go on your side as your update can also assist others in the community who may be facing the same issue.

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