Make sure you have your SpeedController object created and initialized for the right port, if its a Can device, you can get the can ID from the WebView (Plugin or Wirelessly Connect and then go to
http://172.22.11.2/). If the speed controller is plugged into the PWM, then initialize the object with the port labelled. First try setting the motor values independent of drive to make sure they are connected and working. I can provide more specific information if you provide your coding language, speed controllers, and port mapping.