How to Troubleshoot Login Error Code 500121 In Microsoft Intune HTML Blog

Important Points

• Enter Error Code 500121 in Microsoft Intune
• This is not a system failure but a authentication disturbance
• Security controls are working properly
• Admins must monitor repeated failures potential risk signals

Let’s discuss How Solve the problem Login Error Code 500121 in Microsoft Intune. Recently, some users noticed that some login failures were related to Multi-Factor Authentication (MFA). This was found in Log in under the Users section. The log shows that the user exists failure during the strong authentication step.

How to Troubleshoot Login Error Code 500121 in Microsoft Intune

In Microsoft Intune, Sign-in details show that the error is shown at Error code 500121. This means login failed while trying to complete MFA. MFA is required, but the user did not successfully complete the verification process. It doesn’t mention that the password is wrong.

Where You Can Find This Error

You can find this error in Log in in the Microsoft Intune admin center. Go to User >Log in, then open the failed attempt to view detailed error message and reason for failure. Here, in the figure, it can be seen that the reason for the failure is Authentication failed during a strong authentication request.

Cause of this Problem

The main reason you see the error 500121 is it Multi-Factor Authentication (MFA) step is not complete. Even if you enter your password correctly, the sign-in process will fail if you do not accept notifications in your account telephoneentering the wrong code, or not responding before the request expired. Sometimes this can also happen because of small thingstechnical problems.

Solution – Try again Sign in and Complete MFA

In Solution options, there are several methods to solve this problem. One of the easiest ways is to ask the user to log in again and complete it carefully MFA command. Users must agree to it announcement or enter the verification code within the time limit.

Check the Internet Connection

Make sure the phone is of better quality Internet connection and MFA command not ignored or cancelled. When the network slows down, this will happen toAuthentication process.

See More: Fix No Internet Issue on Mobile Hotspot Connection in Windows 11

Resetting Authenticator

You can try Resetting Authenticator. If the user can’t solve it Ministry of Foreign Affairsreset existing MFA method from admin center. After resetting, ask the user to sign in again and set up MFA from scratch. This helps fix problems caused by Wrong MFA arrangement.

See More: Azure AD SSPR Self-Service Password Reset Guide

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Author

Anoop C Nairhas been Microsoft’s MVP for 10 consecutive years from 2015 onwards. He is a Workplace Solutions Architect with over 22+ years of experience in the Workplace technology space. He is a leader of the Community of Bloggers, Speakers, and Local User Groups. The main focus is on Device Management technologies such as SCCM and Intune. He writes about technologies like Intune, SCCM, Windows, Cloud PC, Windows, Entra, Microsoft Security, Career, etc.