USB compatible (or not) devices list

[Lizard of Oz]

I just tried the Polyend Synth with the MRCC, and it doesn't seem to work. 

When I connect the Synth to one of the USB ports, it powers up reliably, and I can route MIDI to that port. 

However. the LED next to the physical USB port on the MRCC does not light up, and the Synth does not receive MIDI messages, and the MCRR does not indicate that it receives MIDI messages from the Synth.

I have tried other devices on the same USB port, and they work, so it's not the port, I would guess. What can be done to fix this?