We have Windows Server 2012 Standard as a remote desktop server, and older legacy thin clients cannot connect to it. Is there guidance that indicates the minimum required version of RDP to connect to Server 2012?
When we activated a license server on our 2012 Standard RDS server, some of the thin clients started receiving an error when they connect: "Remote Desktop disconnected because of a security error. The client cannot to the remote computer. verify you are logged on the network and try connecting again"
The server also logs "A fatal alert was generated and sent to the remote endpoint. This may result in termination of the connection. The TLS protocol defined fatal error code is 10. The Windows SChannel error state is 10."
We believe that the version of RDP on the thin client dictates whether or not it can connect.
Windows 8, Windows 7, and Windows XP SP3 can connect, as can newer thin clients.
We have unchecked the "Allow connections only from computers running Remote Desktop with Network Level Authentication (recommended)" located on the Remote tab of System Properties, and on Server Manager\Remote Desktop Services\Collections[servername]\Properties of the collection->Tasks->Edit Properties. However, older thin clients still cannot connect.
I can't find an authoritative answer from Microsoft as to exactly what version(s) of RDP are supported to connect to RDS under Server 2012.