Problem with MFA for user @zonik.onmicrosoft.com

Question

I try to log with my account "[Moderator note: Personally Identifiable Information removed]@zonik.onmicrosoft.com" for VLSC to access to my perpetual licenses and transfer licenses to 365 Admin console.

I have problem with MFA:

Error Code: 399287

Request Id: [Moderator note: Personally Identifiable Information removed]

Correlation Id: [Moderator note: Personally Identifiable Information removed]

Timestamp: 2026-08-27T12:12:18Z

Please reset MFA or help to access to my perpetual licenses.

My 365 Admin user is [Moderator note: personal information removed]

Answer 1

Hello @Zoran Nikolovski

Error code 399287 usually appears when signing in to Microsoft services like Admin Center, Azure, Microsoft 365, Outlook, or Teams. It typically points to a problem during the identity verification step, often related to multi-factor authentication (MFA). 

Here are some steps you can do to troubleshoot this issue: 

1. Try an Alternative MFA method: 

Please kindly try any alternative MFA methods you have set for your account (sms, phone, authenticator app) 

2. Reset MFA methods 

If you still can sign in to your administrator account in your browser or you tenant has another global admin, please try to reset the MFA methods. Once reset, we recommend re-registering MFA using the Microsoft Authenticator app instead of SMS. 

In the Entra admin center, an administrator can set user accounts to require a re-enrollment of multi-factor authentication (MFA). Ask your administrator to follow the steps shown in the following article: 

Manage user authentication methods for Microsoft Entra multi-factor authentication 

• Sign in to Microsoft Entra - Microsoft Entra admin center 
• User -> all users. Select the user you want to act on, and then select "Authentication methods". then select "Require multi-factor authentication re-registration". 

Require re-enrollment MFA: This disables all previous authentication methods. You'll then be prompted to set up a new MFA authentication method the next time you try to sign in, so you can add a new authenticator app. 

3/ Contacting Microsoft Data Protection team by phone support

In this situation, the Microsoft Data Protection team has tools and processes in place to verify identity and regain access to administrator accounts.     

Therefore, if you are the only administrator in your organization, then you need to involve Microsoft data protection team. Please try to find the related hotline number to call the frontline let them raise a ticket for you: Customer service phone numbers - Microsoft Support

If you can use English, you may prefer these numbers:

(Important Note: Depending on your country or region, when you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)

In some countries, this is an automated conversation: First, when you call the hotline, they will ask you what kind of problem you are struggling with.

Answer: Authenticator.

A: What products do you use?

B: Office 365 for business.

Verification: Education or company account?

B: For companies

A: Are you an administrator?

B: Yes.

A: Are there any other administrators in your organization?

B: No.

A: I need one.... Service request?

B: Yes  

If your organization's Office 365 Business subscription is from a partner or reseller, and the global administrator is unable to open a service request on your end, contact the reseller's support provider to help open a service request on behalf of you instead.

Please try "2 or 3"times until you can reach out to an agent.

Wish you all the best!

Answer 2

Hi Zoran,

Error 399287 usually means Microsoft has blocked the registered phone number for SMS verification. This cannot be reset through this public forum.

If another administrator exists in the zonik.onmicrosoft.com tenant, ask them to remove your old authentication method and require MFA re-registration. Your administrator account in lotomk.onmicrosoft.com cannot perform this reset unless it also has the required role in the Zonik tenant. If you are the only administrator, contact Microsoft 365 Support and request a tenant-access/MFA escalation.

Also, VLSC was retired in April 2024. Perpetual licences are now under Microsoft 365 admin center > Billing > Your products > Volume licensing. If you cannot access the original account, submit a Volume Licensing Support request and ask Microsoft to create or transfer the VL profile to your accessible Entra account. Include the agreement number, registered business email and both tenant details privately.

Thank you, and feel free to respond back for more assistance.