Windows Server 2025 will not allow my domain users to access a server's shared folder

Question

I need assistance with a problem regarding my new Windows Server 2025. My domain users are unable to access the server's shared folder.
We have a Windows Server 2025 Standard set up, and I have configured all the necessary shared permissions and security settings.
However, I cannot see the UNC path from my Windows 11 workstation, which is on the same network.

Additionally, could you provide me with the best contact number for Microsoft Windows Server support?

I am unable to create a support ticket online as it doesn't accept my Subscription ID.

Please advise.
Juan Maldonado

Answer 1

Juan Maldonado TX

The issue perhaps is rooted in the massive Server Message Block security hardening Microsoft introduced in Windows Server 2025. If your Windows 11 workstation is running an older build, or if a legacy Group Policy is disabling SMB signing on the client side, the server will instantly reject the connection without prompting for credentials, leaving the UNC path completely inaccessible.

To rule out an authentication protocol failure, ensure your users are not attempting to access the shared folder using the server's IP address or a short NetBIOS name. Windows Server 2025 has deprecated NetBIOS and enforces strict NTLM blocking. When you connect via an IP address, Windows falls back to legacy NTLM authentication, which the new security baselines will drop. You must explicitly map the network drive using the server's Fully Qualified Domain Name, such as \server.yourdomain.local\ShareName. Using the complete domain name forces the operating system to negotiate using the modern Kerberos authentication protocol, which satisfies the server's strict security requirements.

You should also verify that the SMB signing policies are perfectly aligned between the workstation and the server. On your Server 2025 machine, open the Registry Editor and navigate to the path HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManServer\Parameters. Look for the registry DWORD named RequireSecuritySignature and ensure it is set to 1. You can achieve the same check by opening an elevated PowerShell window and running the command Get-SmbServerConfiguration | Select RequireSecuritySignature. You must run the equivalent check on the Windows 11 workstation using Get-SmbClientConfiguration | Select RequireSecuritySignature to ensure the client is also enforcing the signature, otherwise the secure connection will fail.

VP

Answer 2

May be stupid question. Are you sure your Windows 11 are Pro, not the Home edition?

Answer 3

I have done all of this, and I am still having issues with the Windows Server 2025 sharing folder. Any other answer will be greatly appreciated.

Answer 4

Hi Juan Maldonado TX,

The issue you are facing is tied to a confirmed Network Location Awareness bug currently affecting Windows Server 2025. After a reboot, the operating system occasionally fails to authenticate with the domain quickly enough and incorrectly applies the restrictive Public firewall profile instead of the Domain profile. This misclassification automatically blocks incoming SMB traffic, which perfectly explains why your permissions are correct but the UNC path remains completely invisible to your Windows 11 workstation.

To fix this, you need to force the server to re-evaluate its network connection. You can do this by opening an elevated PowerShell window on your Server 2025 machine and running the command Restart-NetAdapter. Please note that if you are managing this server remotely via a remote desktop session, this command will temporarily drop your connection as it safely resets the network interfaces. Once the adapter comes back online, it should correctly identify the domain network, apply the proper firewall rules, and immediately restore access to your shared folders. Since this is an OS-level bug, you may need to repeat this step after future reboots until Microsoft releases a permanent patch in a cumulative security update.

If you still need to get in touch with Microsoft Enterprise Support regarding the bug or your Subscription ID portal issue, calling them directly is your best route. You can bypass the online ticketing system by dialing their official business support line at 1-800-865-9408 if you are in the United States. They can manually route your case to the server team without requiring the online portal validation.

Hope this answer brought you some useful information. If it did, please hit "accept answer". Should you have any questions, feel free to leave a comment.

VP

Answer 5

On Windows Server 2025, there is a known issue where domain controllers might not manage network traffic correctly after a restart and might not be reachable on the domain network. This can affect access to shared folders from domain-joined clients.

If the Windows Server 2025 machine hosting the share is a domain controller, do the following on that server after a restart:

1. Restart the network adapter so the correct domain firewall profile is applied:
   • Open an elevated PowerShell window.
   • Run:

          Restart-NetAdapter *
     

   • After the adapter restarts, try accessing the UNC path again from the Windows 11 workstation.
2. Because this issue recurs after every restart, configure an automatic workaround until the fix is installed:
   • Create a scheduled task that runs at system startup and executes Restart-NetAdapter * with highest privileges.
3. Permanently fix the issue by installing the June 10, 2025 Windows security update or any later cumulative update on the Windows Server 2025 machine:
   • Install update KB5060842 or a newer security update for Windows Server 2025.
   • After installation and reboot, the domain controller should correctly use the domain firewall profile and shared folders should be accessible without needing the adapter restart workaround.

For help contacting Microsoft about Windows Server or Windows Update issues, use one of these options from a supported device:

• Open the Get Help app in Windows and follow the prompts to reach Microsoft Support.
• Go to the Microsoft Support site at support.microsoft.com and use the Windows Server support options.
• For organizational support, use the Support for business portal (support.serviceshub.microsoft.com/supportforbusiness/onboarding).

If the subscription ID is not accepted when creating a support ticket, use the Get Help app or the Support for business portal to open a case and have support validate the subscription details.

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References:

• Resolved issues in Windows Server 2025
• Windows Server 2025 known issues and notifications