I have a Server 2012 level domain with a Server 2012 RDS server running all the roles on one machine with a default collection. Everything works just fine. As a part of the RDWeb App page you have the "Connect to a remote PC" link at the top. This works beautifully for administrators. However, most all domain users are by default standard users and this link fails for them with the above error. I've added/enabled all the recommended GPOs to allow connection through Remote Desktop that I've been able to find through searches but still this problem persists. If I change the user to be a local administrator on their workstation (not desirable) it works just fine. What am I missing or failing to consider?
I tried adding the group \Domain Users to the Remote Desktop Users security group and that didn't work either so I removed it as they don't need access to the DC. I see many other discussions around this error but I haven't found the answer I need.