Using classic Outlook for Windows in business environments
Hi Bridget,
That banner indicates that Outlook is unable to verify the sign-in session for your account requires the account to be re-authenticated.
To help narrow down the cause, could you please let me know:
- What happens when you click "Sign in via browser"?
- Does the sign-in complete successfully?
- Do you receive an error message or repeated password prompts?
In the meantime, please try the following steps:
1/ Re-sign in to Office
- Open any Office app and go to File > Office Account.
- Sign out of the affected account.
- Close all Office applications completely.
- Reopen Outlook and sign in again.
This will refresh the Office authentication token that Outlook uses.
2/ Clear saved Office credentials
- Sign out of all Office applications and close them.
- Open Credential Manager in Windows.
- Under Windows Credentials and Generic Credentials, remove entries related to:
- Microsoft 365
- Office
- The affected work account
- Restart the computer.
- Open Outlook or another Office application and sign in again.
- Office
- Microsoft 365
Please remove only credentials that are clearly associated with Microsoft Office or the affected work account
3/ Create a new Outlook profile
A corrupted Outlook profile can sometimes cause authentication issues.
- Close Outlook.
- Open Control Panel > Mail > Show Profiles.
- Select Add to create a new profile.
- Add and sign in to the work account.
- Set the new profile as the default and test Outlook.
For more information, please consult Create a profile in classic Outlook for Windows | Microsoft Support
To help with further troubleshooting, please share the results of the above steps. Additional details will help determine whether the issue is related to Outlook, stored credentials, or the account's authentication settings.