Teams AADSTS900144

The error message AADSTS900144 indicates that the request body is missing the login_hint parameter, which is required for Azure Active Directory (AAD) to identify the user account during authentication. This issue often arises when switching between accounts in Microsoft Teams, especially when dealing with guest accounts.

Here are some steps you can try to resolve the issue:

1. Ensure Correct Account Switching

• When switching to the guest account, ensure you are selecting the correct account from the account picker. Sometimes, the account picker might not properly pass the login_hint parameter.
  • If the account picker does not appear, try manually signing out of all accounts and then signing back in.

2. Manually Provide the login_hint Parameter

• If you have access to the URL or configuration where the authentication request is made, ensure the login_hint parameter is included with the guest account's email address.
  • Example: https://login.microsoftonline.com/common/oauth2/authorize?client_id=...&login_hint=******@domain.com

3. Clear Teams Cache

• Completely clear the Teams cache, as cached data might be causing the issue.
• On Windows:
  1. Close Microsoft Teams.
  2. Navigate to %appdata%\Microsoft\Teams and delete all files and folders.
  3. Restart Teams and try logging in again.

https://learn.microsoft.com/en-us/microsoftteams/troubleshoot/teams-administration/clear-teams-cache

4. Reinstall Microsoft Teams

• Uninstall Microsoft Teams completely, including any residual files, and then reinstall the latest version.
  • After reinstalling, log in with your personal account first, then try switching to the guest account.

5. Check Tenant Configuration

• Ensure the guest account is properly configured in the Azure AD tenant.
  • Verify that the guest account has the necessary permissions and that the invitation has been accepted.
  • If possible, ask the tenant administrator to reissue the guest invitation.

6. Use the Web Version of Teams

• Since you mentioned that everything works perfectly in the browser, consider using the web version of Teams as a temporary workaround.
  • Access Teams via https://teams.microsoft.com.

Contact Microsoft Support**

• If none of the above steps work, consider reaching out to Microsoft Support for further assistance. Provide them with the error code (AADSTS900144) and detailed steps to reproduce the issue. https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide

Additional Notes:

• The login_hint parameter is used to pre-fill the username field during login, which can help Azure AD identify the correct account. If this parameter is missing, the authentication flow might fail, especially when dealing with guest accounts.
• https://learn.microsoft.com/en-us/entra/identity-platform/reference-error-codes
• Ensure that your personal account and guest account are not conflicting in any way (e.g., same email address used for both).

you have to contact the related company organization’s IT admin who has added you as a guest member in their organization. They should open service ticket for your issue.

For my provided answer, you may share your vote so other users can get correct instructions in this case url.

This was fixed for me last week by Teams auto-update, new version was released.

Following the suggested link by Techhelp Volunteer https://learn.microsoft.com/en-us/microsoftteams/troubleshoot/teams-administration/clear-teams-cache

I solved the issue applying the Method 1: Reset the app (https://learn.microsoft.com/en-us/microsoftteams/troubleshoot/teams-administration/clear-teams-cache#method-1-reset-the-app)

Thanks!