Windows 7 is running Remote Desktop Protocol version 7 (RDP 7). Since we are using Windows 7 we run into following problem.
There was little valuable information on the Internet to solve this problem. To fix this problem a client was reinstalled. In the end there was a simple solution fix this problem to connect to remote systems.
The problem was not on the remote desktop or terminal server but on the client itself.
How to fix remote desktop error in licensing protocol?
Right-click on “Remote Desktop Connection” shortcut in the Start Menu and click on “Run As Administrator” once. Logon as Administrator and connect to the remote system.
Reboot the system and RDP session will work again. If the system is used by a regular user the connection will work now.