Lately I had a RDS Terminalserver that was a Stand-Alone server. So all services were installed on this one Server (Windows Server 2012 R2).
I had a RDS User CAL for 10 User CALs. They were installed. After a crash of the server because the connection to the Shared Storage for the VM was lost, the users were not able to login to the server anymore. In the Remotedesktop License Manager the CAL was available with a Total of 10 CALS but with 0 available and 0 in use. In general it should be available + in user = total.
I reinstalled the RDS License Manger Feature without any changes. I searched the Web and finally found the solution here: https://social.technet.microsoft.com/Forums/ie/en-US/dcfb1966-89a8-4b5d-bf5a-ff03ac0b7a66/rds-cal-licenses-not-recognized?forum=winserverTS
The solution is:
1. Disable the License Server in the License Manager (Right Click the Server => Advanced => Deactivate Server)
2. Uninstall the License Server Feature. Your server have to restart to finish this action.
3. Rename the Folder C:\Windows\System32\lserver to lserver.old (or something else). This resets the License server incl. the currently available CALs. That way you will be able to reinstall them.
4. Install the License Server Feature (no restart required)
5. Activate the Server in the License Server Manager (Right Click the Server => Activate Server)
6. Install and activate the CALs
The result will be a total amount of 10 CALs where 10 are available and 0 are in use (until the first users will connect).