Server 2012 RDS ‘there are no Remote Desktop License Servers available to provide a license.’

Server 2012 RDS ‘there are no Remote Desktop License Servers available to provide a license.’

On a Server 2012 RDS farm that has been deployed and working for some time you begin to receive errors stating ‘The remote session was disconnected because there are no Remote Desktop License Servers available to provide a license. Please contact the server administrator.”

You verify your configuration is as expected, that you have valid CALs installed on a Server 2012 terminal server licensing server and that the RD Licensing Diagnoser doesn’t report any errors.

The issue may be that there is a bug with Server 2012 RDS session hosts where they will not look to the licensing server for CALs when the grace period ends. Microsoft are reportedly aware of this but as yet there is no KBA or hotfix for it.

The solution is to open the registry editor on the affected session hosts and browse to the following:

HKLMSystemCurrentControlSetControlTerminal ServerRCM

If the ‘GracePeriod’ key exists you will need to delete it.

If the licensing configuration appears to be correct and the RD Licensing Diagnoser reports no problems, please perform the following steps:

1. Open Registry Editor (regedit).
2. Go to HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlTerminal ServerRCM. Export this registry key to a file before making any changes.
3. Locate the GracePeriod key and either delete or rename it. It may be necessary to take ownership of the key and/or modify its permissions first.
4. Reboot the RDSH server. You should now be able to successfully connect to it.