Windows Server 2012 R2 “RDP error”

Hello there

We have got windows server 2012 R2 with RDS installed. When client tries to do the Remote Desktop connection time the server, they receive the repititive error saying “An internal error has occurred” before they are finally allowed to log in.

This happens to only this server no matter from where we tried to do the RDC to that server.
Is there any solution to get rid of the error.?