Error: Unhandled Exception Has Occurred In Your Applicattion. Cannot Access A Di

This is my first time using ARC. Received the error above when trying to add a wireless joystick to control two modified servos for Wall-e project. I thought I followed exact steps as depicted in joystick tutorial video. ARC recognizes joystick because the various rows highlight in configuration window when I press joystick buttons. When I try to use analog sticks though, nothing happens. I did assign right wheel and left wheel to D0 and D1 where they are plugged in. When I use keyboard arrows, they work as expected as well, jst not with joystick/controller. Using a wireless xbox controller for Windows.

Any suggestions? Also posted a video reply to joystick tutorial video on YouTube showing what I did.

Thanks.

Brian