Microsoft Entra MFA Error 399287 prevents verification for multiple taalim.ma accounts

Amalo Amlanji 0 نقاط السُمعة
2026-07-12T22:21:40.6333333+00:00

Hello Microsoft Team,

We are experiencing the same Microsoft Entra Multi-Factor Authentication (MFA) problem with several [Moderator's note: PII removed] education accounts, not just one account.

When users sign in, Microsoft asks them to verify their identity using SMS or Phone Call. Before any verification code is sent, the following message appears:

"Sorry, we're having trouble verifying your account. Please try again."

The troubleshooting details are:

  • Error Code: 399287
  • Request Id: [Moderator's note: PII removed]
  • Correlation Id: [Moderator's note: PII removed]
  • Timestamp: 2026-07-12T21:22:08Z

We have already tried all common troubleshooting steps:

  • Different browsers (Chrome, Edge, Firefox, etc.)
  • Incognito/InPrivate mode
  • Clearing cache and cookies
  • Different computers
  • Different mobile phones
  • Different Internet connections (Wi-Fi and mobile data)
  • Proxy and VPN disabled
  • Correct system date and time
  • Different user accounts

The problem still occurs and affects multiple taalim.ma accounts.

Could you please answer the following questions?

  1. What exactly does Error Code 399287 mean?
  2. Is this related to Microsoft Entra MFA, Phone Reputation, or another security protection?
  3. Can this issue be caused by a blocked phone number or a blocked authentication method?
  4. Can a Microsoft Entra administrator resolve this by:
    • Removing the current Authentication Method?
      • Requiring MFA re-registration?
        • Issuing a Temporary Access Pass (TAP)?
        1. If none of the above works, does Microsoft need to remove a server-side block or investigate this account?

We would appreciate any technical explanation or official documentation regarding Error Code 399287 because this issue is affecting multiple users.

Thank you.Hello Microsoft Team,

We are experiencing the same Microsoft Entra Multi-Factor Authentication (MFA) problem with several [Moderator's note: PII removed] education accounts, not just one account.

When users sign in, Microsoft asks them to verify their identity using SMS or Phone Call. Before any verification code is sent, the following message appears:

"Sorry, we're having trouble verifying your account. Please try again."

The troubleshooting details are:

  • Error Code: 399287
  • Request Id: [Moderator's note: PII removed]
  • Correlation Id: [Moderator's note: PII removed]
  • Timestamp: 2026-07-12T21:22:08Z

We have already tried all common troubleshooting steps:

  • Different browsers (Chrome, Edge, Firefox, etc.)
  • Incognito/InPrivate mode
  • Clearing cache and cookies
  • Different computers
  • Different mobile phones
  • Different Internet connections (Wi-Fi and mobile data)
  • Proxy and VPN disabled
  • Correct system date and time
  • Different user accounts

The problem still occurs and affects multiple [Moderator's note: PII removed] accounts.

Could you please answer the following questions?

  1. What exactly does Error Code 399287 mean?
  2. Is this related to Microsoft Entra MFA, Phone Reputation, or another security protection?
  3. Can this issue be caused by a blocked phone number or a blocked authentication method?
  4. Can a Microsoft Entra administrator resolve this by:
  • Removing the current Authentication Method?
    • Requiring MFA re-registration?
      • Issuing a Temporary Access Pass (TAP)?
      1. If none of the above works, does Microsoft need to remove a server-side block or investigate this account?

We would appreciate any technical explanation or official documentation regarding Error Code 399287 because this issue is affecting multiple users.

Thank you.

Microsoft Teams | Microsoft Teams للأعمال | التسجيل وتسجيل الدخول | تسجيل الدخول
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فرز حسب: الأحدث
  1. Huy-K 13,990 نقاط السُمعة فريق عمل موظفين Microsoft الخارجيين المشرف
    2026-07-13T00:21:25.19+00:00

    Note: As the thread is posted on a Arabic link but written in English, I will kindly respond in English for consistency.

    ,Dear @Amalo Amlanji

    Please note that since your account is belonged to an organization, none of moderators could help you with this while your account are belonged to an organization to do this action. Kindly follow these steps:

    If you are an end-user or there are other Global Admin in your tenant:

    Please contact your IT Admin to revoke your MFA. Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | Microsoft Learn

    If you are the only Global Admin:

    Option 1: You may need to contact the Data Protection Team at the service phone number via this link: Customer service phone numbers - Microsoft Support.

    The main objective is to go through the IVR (automated system) until you reach a live agent and emphasize this very important security factor. Please help me try this script below, this is a commonly used script for authentication issues to bypass IVR, but you can try to see if it helps get through the system. Please help me to speak loudly, only keywords, clearly and patiently waiting for the machine's response. First, when you call the hotline, they will ask you what kind of problem you are facing with.

    Answer: Authenticator.
    A: What products do you use?
    B: Office 365 for business.
    Verification: Education or corporate account?
    B: For companies
    A: Are you an administrator?
    B: Yes.
    A: Are there other administrators in your organization?
    B: No.
    A: I need one.... Service request?
    B: Yes
    

    During the call, you must provide information related to the subscription, such as your company name, billing history, phone number, and alternate email address. This information helps data protection teams verify identities and securely regain access to administrator accounts.

    Option 2: Create a new tenant with trial subscription to access and submit a ticket in the Admin Center.

    If you still can't get in touch with a real person for help, help me try the following:

    Sign up for a free trial (new tenant with trial subscription) of Microsoft 365 at this link: Compare All Microsoft 365 Plans | Microsoft. The goal is to create a temporary tenant with a Global Administrator account so that you can sign in to the Microsoft Admin Center. Once connected, you can submit a support ticket directly to Microsoft. Please remember to cancel the trial subscription once your issue is resolved to avoid unwanted charges.

    How to submit support ticket in Admin Center: Get support - Microsoft 365 Admin | Microsoft Learn

    Once you contact the Data Protection team, you will be required to provide proof of ownership of the company. This allows them to verify their identity and help reassign the Global Administrator account.

    In addition, you can also create new thread in this forum Microsoft Security Microsoft Entra Microsoft Entra ID - Microsoft Q&A for further support.

    As a moderator, I do not have the tools to investigate your specific account directly, as this is a support forum between users. Moderators and collaborators, including external Microsoft employees, may not directly intervene in the functionality of Microsoft products or access internal systems. Our role is limited to providing technical guidance on reported problems, requests, or ideas. However, I will do my best to guide you as clearly as possible.


    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

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