Outlook MFA Token Prompt Loop: How to Clear From Credential Manager

You are repeatedly asked for your multi-factor authentication token every time you open Outlook, even after you enter the correct code. This MFA prompt loop occurs when Outlook stores an expired or corrupted authentication token in Windows Credential Manager. The stored credentials no longer pass the server’s validation, so Outlook requests a fresh token on each launch. This article explains why the loop happens and provides the exact steps to clear the stale credentials from Credential Manager so Outlook can request a new, valid token.

Why Outlook Keeps Asking for Your MFA Token

When you sign in to Outlook with a Microsoft 365 account that uses multi-factor authentication, Outlook stores an authentication token in Windows Credential Manager. This token is valid for a specific duration set by your organization’s conditional access policies. After the token expires or becomes corrupted, Outlook cannot reuse it. Instead of silently requesting a new token, Outlook falls back to prompting you for the MFA code each time it starts.

The loop persists because the old token remains in Credential Manager. Outlook checks this cached token first and fails to validate it. The error triggers a new MFA challenge, but the expired token is never removed. On the next launch, Outlook finds the same invalid token and repeats the cycle.

Common triggers for this issue include:

• A recent password reset or MFA device change
• An Office update that modifies authentication components
• Switching between work and personal Microsoft accounts on the same device

Steps to Clear Outlook MFA Tokens From Credential Manager

1. Close Outlook completely
   Right-click the Outlook icon in the system tray and select Exit. Verify Outlook is not running by opening Task Manager with Ctrl+Shift+Esc and checking for Outlook.exe in the Processes list. If present, select it and click End Task.
2. Open Windows Credential Manager
   Press the Windows key, type Credential Manager, and select the result. Alternatively, open Control Panel, set View by to Large icons, and click Credential Manager.
3. Go to Windows Credentials
   Click the Windows Credentials tab. This section stores all cached logins for Windows applications, including Outlook and Microsoft 365.
4. Locate Outlook and Microsoft 365 credentials
   Scroll through the Generic Credentials list. Look for entries that contain the words MicrosoftOffice, Microsoft.Office, Outlook, or Microsoft.Azure. Common examples include MicrosoftOffice16_Data:ADAL:… and Microsoft.Azure.ActiveDirectory:….
5. Remove each related credential
   Click the arrow next to an entry to expand it. Click Remove and confirm the deletion. Repeat for every entry that matches the search terms above. Do not delete credentials for other applications unless you are certain they are not needed.
6. Restart Outlook
   Open Outlook normally. The first time it launches, Outlook will detect that no cached token exists. It will prompt you to sign in again and request a new MFA code. Enter your password and the verification code from your authenticator app or hardware token.
7. Verify the loop is resolved
   Close Outlook and reopen it. You should not see the MFA prompt again unless the token expires naturally. If the prompt appears again immediately, repeat steps 1 through 6 and check for any credentials you might have missed.

If Outlook Still Prompts for MFA After Clearing Credentials

Outlook prompts for MFA on every launch even after deleting all credentials

This usually means a second credential store still holds the invalid token. The Microsoft 365 Apps for enterprise suite stores tokens in a separate location called the ADAL token cache. To clear this cache:

1. Close Outlook
   Exit Outlook using File > Exit or by ending Outlook.exe in Task Manager.
2. Open the Run dialog
   Press Windows key + R, type %localappdata%\Microsoft\Office\16.0\Licensing, and press Enter.
3. Delete the Licensing folder contents
   Select all files and folders inside the Licensing folder and delete them. Do not delete the folder itself.
4. Restart Outlook
   Outlook will rebuild the licensing cache and prompt for a fresh sign-in.

Outlook shows “Cannot start Microsoft Outlook” after credential removal

This error appears when the Outlook profile itself is corrupted, not the credential store. Create a new profile:

1. Open Mail settings in Control Panel
   Press Windows key + R, type control mlcfg32, and press Enter.
2. Click Show Profiles
   Select your current profile and click Remove. Confirm the deletion.
3. Create a new profile
   Click Add, name the profile, and enter your email address. Outlook will set up a fresh profile and request a new MFA token.

MFA prompt loop returns after a few days

Your organization’s conditional access policy may have a short token lifetime. Contact your IT administrator to check the sign-in frequency policy in Azure AD. If the policy requires reauthentication every 24 hours, the loop is expected behavior. If the policy allows longer sessions, the issue may be a misconfigured token lifetime setting.

Item	Windows Credential Manager	ADAL Token Cache
Description	Stores generic credentials for Windows applications	Stores authentication tokens for Microsoft 365 apps
Access method	Control Panel > Credential Manager > Windows Credentials	%localappdata%\Microsoft\Office\16.0\Licensing
What to delete	Entries with MicrosoftOffice, Outlook, or Microsoft.Azure	All files and folders inside the Licensing folder
When to use	First step for MFA prompt loop	If Credential Manager cleanup does not resolve the loop

Clearing the cached credentials from Windows Credential Manager is the primary fix for the Outlook MFA token prompt loop. If the problem persists, delete the ADAL token cache in the Licensing folder. For recurring prompts, check your organization’s conditional access policies. After clearing the credentials, Outlook will request a new authentication token and stop the loop.