usb_control_msg works in linux but not windows

Good day...

We are writing some proof of concept software to ensure a new USB device 
will be usable in both Linux and Windows.

The following line turns on an LED.

     int t2 = usb_control_msg(handle, 0x01, 10, on   , 0, 0, 0, 10);

and works just fine in Linux, however produces the following error in 
Windows:

     libusb0-dll:err [control_msg] sending control message failed, win 
error: The parameter is incorrect.

I am very new to USB, and have not been able to find any kind of 
reference as to why it would work on one side, but not the other... Any 
help would be most appreciated.

Rob




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