In order to be able to use "native RDP" or the RDP Client in the thin clients, there are settings that must be configured. 

First, from the VERDE Management Console.  You must enable Direct RDP  in the Configuration/General Settings/General Setting user interface as follows:

Now, you need to modify two setting on the RX Devices.

Select RDP Client as follow on the Settings (little gear on screen) General Page:

Now, access the Connections page and input your server IP or server URL with the following checkboxes:

You should now be able to access your VERDE VM's via RDP Client (native rdp).