Error "We didn’t hear from you" signing in to Microsoft 365 Copilot. Error Code: 500121

Q. When attempting to sign in to Microsoft 365 Copilot, I’m not receiving push notifications from the Microsoft Authenticator app. As a result, I get the error message: "We didn’t hear from you" Error Code：500121

A. Please authenticate your phone number by following the steps below.

This error occurs when authentication via the Microsoft Authenticator app is not completed and times out.

For more detailed information about error codes, please visit Microsoft Learn.
Reference: How to troubleshoot sign-in errors - Microsoft Entra ID | Microsoft Learn

If you don’t receive a notification from the Microsoft Authenticator app, please authenticate using your phone number by following the steps below.

1. Click "get a code a different way" in the error message window.
   
    
2. Please select either "Send SMS" or "Call me" to proceed.
   
   1. If you select "Send SMS", please enter the verification code sent to your phone and sign in to Microsoft 365 Copilot.
   2. If you select "Call me", you will receive a phone call. Follow the automated voice instructions to complete the sign-in process.

If you haven’t registered a phone number or your phone number is unavailable, please contact us using the inquiry form.

・THERS Account Help Center Contact Form