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Windows Server 2025 would not let me log in after promoting it to domain controller

John Ekpenyong 0 Reputation points
2025-08-15T15:47:40.76+00:00

When we do in-place upgrade a domain controller to Server 2025, or promote an existing Server 2025 VM to a domain controller, it is then not possible to log in to that VM. All you get when you attempt to log in is "The username or password is incorrect".

But this is not true as that username ad passowrd is able to log in to the other domain controllers that are still Windoes server 2019.

Please can soomeone point me to where I may be doing something wrong?

Windows for business | Windows Server | Directory services | User logon and profiles
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  1. Domic Vo 11,700 Reputation points Independent Advisor
    2025-09-14T18:12:57.6933333+00:00

    Dear John Ekpenyong,

    This issue has been observed in some environments and may be related to Kerberos authentication failures or LocalKDC service behavior introduced in Server 2025. In certain cases, the LocalKDC service may not start correctly, especially after updates like KB5048667 or KB5055523, preventing proper domain authentication.

    We recommend checking the following:

    Ensure DNS replication and time synchronization are functioning correctly across all domain controllers.

    Temporarily disable the LocalKDC service or set it to Manual if not using Windows Hello or certificate-based logins.

    Confirm that the domain trust relationship is intact and that the promoted DC is properly registered in Active Directory Sites and Services.

    If the issue persists, we suggest escalating through your Microsoft 365 Admin Center or contacting Microsoft Support for guided remediation.

    I hope this helps. Just kindly tick Accept Answer that others in the community facing similar issues can easily find the solution. Your contribution is highly appreciated.

    Best regards,

    Domic Vo

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