Microsoft Authenticator - Error Code: 500121

Question

Hello there!

I want to login (it's an account provided by my school for us teachers); I'm getting a Authenticator Code (as usual), however, after typing the Code into my smartphone, nothing happens.

I deinstalled and reinstalled the App.

Now, when trying to login, I get the following message and code:

Error Code: 500121

Request Id: ***

Correlation Id: ***

Timestamp: ***

I now have no option to login; either this error code appears or I actually get a new code, but have no way to activate this email adress in the app...

What should and can I do?

Answer 1

I see that you wrote your message in English, so I’ll respond in English as well. If anything is unclear, please don’t hesitate to let me know.

Dear @Kevin Liebing,

For a quick resolution, please reach out to your IT or admin team and ask them to reset the MFA methods for the affected users.

Below is a step-by-step solution tailored for your IT admin to follow to reset MFA for your account

1 – Navigate to Microsoft 365 Admin Center, you can click Identity at the sidebar   

Microsoft 365 Admin Center website: Microsoft 365 admin center   

It will lead you to Microsoft Entra Admin Center (Microsoft Entra - Microsoft Entra admin center) 

Select Users    

Click All users    

 

Click on to the affected account name (your account)   

For example:   

2 – Select "Authentication Methods"  

3 – Click "Require re-register multifactor authentication"    

Next time the user sign in, the system will require them to set up a new authentication method. By using this, the affected user can re-set up the right authentication method  

Also, please make sure your device time Accurate time settings are essential because Microsoft Authenticator generates time-based codes. Here’s what to do:

• Turn on automatic date and time on your device.
• Double-check that your time zone is correct.
• Install any pending operating system updates, as these can affect app performance.

Incorrect time settings or outdated software are common reasons why codes fail and can lead to errors like 500121.

To protect your personal information, I’ve sent all Personally Identifiable Information (PII) to your private message for secure storage and future reference.

If you have any additional questions or need to share information related to PII, please send it through a private message as well. This helps us minimize privacy risks and ensure your data remains protected.

If you need any further assistance, feel free to reach out. We're here to help. Thank you very much for your understanding and your cooperation.

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Answer 2

Hallo Nicolas.

vielen Dank für deine Anfrage.

Anfragen im deutschsprachigen Forum sollten in deutscher Sprache eingestellt werden.

Kontaktiere den Microsoft Support nach der Beschreibung unter https://learn.microsoft.com/de-de/microsoft-365/admin/get-help-support?view=o365-worldwide#phone-support telefonisch.

Auf diesem Weg ist die telefonische Unterstützung zu erreichen. Als Grund des Anrufes muss der Begriff AdminCenter genannt werden

Als Rolle muss angegeben werden Globaler Administrator.

In der Beschreibung des Anliegens muss der Begriff AdminCenter genannt werden.

Im Telefondialog kann im Verlauf auf die Frage nach einem weiteren Administrator mit Neingeantwortet werden, dann wird zu einem Mitarbeitenden weitergeleitet und es kann eine Serviceanfrage erstellt werden.

Ich freue mich auf deine Rückmeldung.

Answer 3

Microsoft 365 MFA / Authenticator Issue – Error 500121

I am desperately looking for help from someone familiar with Microsoft 365, Entra ID or Microsoft Authenticator.

I recently changed to a new phone. My password works correctly and I still have access to my email account. I can even reset my password successfully.

However, I can no longer complete MFA authentication because Microsoft Authenticator is still linked to my old device.

I have already tried:

• Reinstalling Microsoft Authenticator
• Registering the new device
• Password reset
• Recovery options
• Microsoft support channels

The result is always the same: Error Code 500121

I run a business and currently cannot access important Microsoft 365 services, so this issue is having a significant impact on my work.

Does anyone know:

• How to reach a real Microsoft support engineer?
• How to request an MFA reset?
• Whether there is a way to re-register Authenticator without access to the old device?

Any help would be greatly appreciated.

Thank you.Microsoft 365 MFA / Authenticator Issue – Error 500121

I am desperately looking for help from someone familiar with Microsoft 365, Entra ID or Microsoft Authenticator.

I recently changed to a new phone. My password works correctly and I still have access to my email account. I can even reset my password successfully.

However, I can no longer complete MFA authentication because Microsoft Authenticator is still linked to my old device.

I have already tried:

• Reinstalling Microsoft Authenticator
• Registering the new device
• Password reset
• Recovery options
• Microsoft support channels

The result is always the same:
Error Code 500121

I run a business and currently cannot access important Microsoft 365 services, so this issue is having a significant impact on my work.

Does anyone know:

• How to reach a real Microsoft support engineer?
• How to request an MFA reset?
• Whether there is a way to re-register Authenticator without access to the old device?

Any help would be greatly appreciated.

Thank you.