RD Licensing Diagnoser playing up. Session Hosts can't find the Licence Server

Question

Morning all,

Running into a bit of a headache with Remote Desktop Licensing. The RD Licensing Diagnoser is reporting that our licence server isn't available to a subset of our session hosts, even though I can ping it fine and port 135/RPC looks wide open.

What's the best troubleshooting path here to sort out the licence server discovery? I want to make sure I'm checking the right bits regarding GPO overrides vs AD auto-discovery before I start tinkering with the registry. Cheers!

Answer 1

Dear Fath Swift,

When RD Licensing Diagnoser reports that the license server is unavailable despite basic connectivity being fine, the issue is usually with how the session hosts are discovering the license server. By default, RDS session hosts use Active Directory service connection points (SCPs) to locate the license server, but this can be overridden by Group Policy or registry settings. If a GPO has explicitly set the license server name under Computer Configuration → Administrative Templates → Windows Components → Remote Desktop Services → RD Licensing → Use the specified Remote Desktop license servers, that will take precedence. If no GPO is applied, check the registry at HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\LicenseServers to see if a static entry exists.

If neither is configured, the hosts rely on AD auto-discovery, which requires that the license server has published its SCP in AD and that the session hosts have permission to read it. You can verify this by running dsquery * "CN=TS-Enterprise-License-Server,CN=Services,CN=Configuration,DC=..." -scope base -attr dnsName to confirm the SCP is present. If the SCP is missing or permissions are restricted, the hosts will fail to locate the server even though RPC connectivity is fine. In practice, the most reliable troubleshooting path is to confirm whether a GPO override is in place, check the registry for static entries, and then validate that the license server has successfully published its SCP in AD.

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Thank you,

HL.