When attempting to sign in to Office 2016 for Mac using a Microsoft 365 user ID and password, you may encounter the following error message:
Another user from your organization is already signed in on this computer.
Solution
To resolve this issue, use the Keychain Access application to delete all password entries containing “Office”. Follow these steps:
1. Launch the Keychain Access application.
2. In the search field, type Office.
3. Delete all found entries.
Note: You should find between two and six entries.
Close the Keychain Access application and try signing in to Office 2016 for Mac again. This is expected behavior and occurs if you are already signed in to Office 2016 for Mac with a different Microsoft 365 account from the same organization.
4. Additionally, remove all Office applications. Go to Finder > Applications and move them to the Trash.
– Then, reinstall the distribution, which can be downloaded from your Microsoft account.
