How to fix Tag: 657rx Code: 2150121473

Question

When I new add email into Microsoft Outlook desktop, I got a invalid message at below. Please advise how to fix-it:

Correlation Id: 11a4ae0a-803f-446c-86d2-1f24186438e8

Timestamp: 2026-01-14T03:31:33.000Z

DPTI: dde5c79cd991fea5e1e7e965ab6401af0886f97f03c5c113fb1d7eb9f90402e2

Message: The credential is invalid. Unexpected sub status (6008).

Tag: 657rx

Code: 2150121473

Thank you for your support in advance.

KT Team

Answer 1

Hello KTHK,

This error indicates Outlook is failing modern authentication when adding the account, usually due to cached credentials or conditional access policies. The profile container itself is fine, but Outlook cannot validate the token, which triggers the “credential is invalid, sub status 6008” message.

The first step is to clear any cached credentials. Open Windows Credential Manager (control.exe keymgr.dll) and remove all stored entries related to Office365, Outlook, or your mail domain. Then restart Outlook and try adding the account again. If the issue persists, run dsregcmd /status in Command Prompt to confirm the device is properly joined to Azure AD or Hybrid AD; misalignment here often causes token failures. Also check that the machine has correct time synchronization, since clock drift can invalidate authentication tokens.

If you are using MFA or Conditional Access, verify that the policies allow Outlook desktop clients. Sometimes new Outlook builds enforce modern auth differently than older ones, and policies need adjustment. Updating Office to the latest build is also recommended, as Microsoft has patched several credential handling bugs in recent releases. If the account works fine in Outlook Web Access but fails in desktop, repairing Office via Control Panel > Programs > Office > Change > Quick Repair can reset the authentication components.

If none of these steps resolve the issue, collect logs using the Microsoft Support and Recovery Assistant (SaRA) tool, which can diagnose Outlook sign-in problems and provide a remediation path. This ensures you have detailed diagnostic data if escalation to Microsoft Support is required.

I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!

Harry.

Answer 2

To resolve the issue with the invalid credential message in Microsoft Outlook, you can try the following steps:

1. Verify Credentials: Ensure that you are entering the correct username and password for the email account you are trying to add. If you have recently changed your password, make sure to use the updated one.
2. Check Account Status: Log in to Outlook on the web with the same credentials to confirm that the account is active and not blocked for sending spam.
3. Update Outlook: Make sure that your Outlook application is updated to the latest version. Sometimes, outdated versions can cause authentication issues.
4. Check for Multiple Accounts: If you have multiple accounts with the same email address (e.g., a personal and a work account), this can cause conflicts. Consider creating a new alias for the user in Microsoft 365 and using that to set up Outlook.
5. Network Issues: Ensure that there are no network issues preventing Outlook from connecting to the server. You may want to check your firewall settings or any network restrictions that might be in place.

If the problem persists after trying these steps, consider reaching out to Microsoft support for further assistance.

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References:

• Connection to Microsoft Exchange is unavailable error when a Microsoft 365 user tries to set up Outlook
• Sorry, the authentication was not successful error occurs in Dynamics 365 App for Outlook