Dear @TT,
Thank you for reaching out to Microsoft Q&A forum.
I'm sorry to hear you're experiencing the recurring sign-in loop with Outlook. I understand how frustrating this can be, especially when error codes and pop-ups don’t behave as expected.
The error code 657rx typically indicates that your account credentials are not being recognized by Microsoft. This can happen for a few reasons, and I’d like to guide you through some steps to help resolve the issue. These steps are designed to be easy to follow and tailored to your situation.
Since you haven’t specified your account type, I’m assuming you’re using a Work/Business account managed by an organization. Please follow these steps to clear your credentials cache and reset your account information:
- Please sign out your accounts from Office applications, then close all Office applications.
- Open File Explorer, paste the following path, and delete all files and folders. %localappdata%\Packages\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy
- In the Windows search bar, search for "Access Work or School".
- Check if you can see your school account in "Access Work or School".
If you don't see it, please select Connect and add your business account.
If you can see it, please select it and select Disconnect. After that, please click "Connect" and log into your account again to register the device.
- Open the Control Panel on your PC.
- Go to User Accounts > Credential Manager.
- Under both Windows Credentials and Generic Credentials, look for any entries related to your Microsoft 365 business account and Office apps.
- Select and remove those entries.
- Restart your computer and try adding your account in Outlook again.
Download OLicenseCleanup.vbs and run it. In this way, you can use this package to remove the license, clear the stored identities in the registry, and remove the credentials.
You can follow this article: Reset activation state for Microsoft 365 Apps for enterprise - Microsoft 365 Apps | Microsoft Learn to reset activation state
Restart your device.
Reopen Outlook and sign in with the correct account.
If these steps feel too complicated or you’re unsure about any of them, I recommend reaching out to your IT administrator, who can assist with the process on your behalf.
For additional assistance, use this link to find the appropriate contact number from your region: Global Customer Service phone numbers - Microsoft Support
I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this. Thank you for your patience and understanding. I'm looking forward to your reply.
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