Upon trying to connect to RDS Apps or Resources the client receives the error "Your computer can't connect to the remote computer because the Remote Desktop Gateway server is temporarily unavailable." This occurs on Windows Server 2012 and 2012 R2
The solution is to simply remove the incorrect binding from IIS Manager.
This can be done by Opening IIS manager, Navigate to Default Web Site > Open Site Bindings on the right hand menu. Remove the invalid binding.