I just got a ws2000 wireless usb dongle and I haven't been able to make it work with fpv freerider and my DX6i.  I've tried it on macOS and Windows 10 (via bootcamp).  Liftoff works fine with the ws2000 + DX6i.  

Calibration within freerider works ok on the left stick (throttle and yaw) and it works ok for roll on the right stick.  But it doesn't work at all for pitch on the right stick.  On the screen with the little circles nothing moves at all when moving the right stick up/down.

Any ideas?  

If it works for throttle/yaw and roll, it should be possible to get the pitch working too. 

Here are some suggestions:
- Make sure you don't have any other joysticks/controllers connected, that might cause a conflict.
- Make sure you uninstall vJoy and Smartpropoplus if you have them installed. (Their driver messes with things when connecting via USB).
- Make sure you have "Heli" selected as model type on your radio. ("Plane" often doesn't work very well).
- Check if there's a switch on the dongle where you can select different modes.
- Perhaps you can remap the output channel (in the menu of the transmitter) so that the pitch stick sends to another channel.

Hope that helps