I have recently come across an issue where users cannot connect to a Session Host due to a licensing issue.
The following screenshot is presented when users try to connect to the session host.
First things first …. I checked the RD Licencing Diagnoser and no errors showed up (everything green), the session host was configured to point to the licence server, and the licence type was set to User Cal’s.
The root cause of the issue was that the grace period key had not removed on installation of the RD Licencing role.
When I tried to delete the key it returned a permission denied error message. To remove this, I had to go into permissions take ownership of the GracePeriod regkey and then delete it.
(As all ways create a backup of the key first).
Please see the path to the GracePeriod path: