Remote Desktop Licensing Configuration
Do the following on your 2012 R2 Remote Desktop Session Hosts. The only way to configure Remote Desktop Licensing is using group policy (local or domain).
1) For local group policy, run gpedit.msc.
2) Go to Computer Configuration > Administrative Templates > Windows Components > Remote Desktop Services > Remote Desktop Session Host > Licensing.
3) Double-click Use the specified Remote Desktop license servers. Change it to Enabled and enter the names of the RD licensing servers. Click OK.
4) Double-click Set the Remote Desktop licensing mode. Change it to Enabled and select Per User. Click OK.
5) In Server Manager, open the Tools menu, expand Terminal Services and click RD Licensing Diagnoser.
6) The Diagnoser should find the license server and indicate the licensing mode. It’s OK if there are no licenses installed on the Remote Desktop License Server.
NOTE: The group policy should point to your RD licensing servers. if you installed it on your Controllers then you would specify them. Otherwise specify the RD Licensing server names.