This happened to so many teams
at our tournament last Saturday that they had to switch over to competition switches to run the matches. A lot of teams would run fine until the moment they plugged into the tower. One symptom we saw was that the joystick vexnet
key was hot to the touch. Some people were saying it could be wifi interference within the building. This didn't seem logical to me because I thought it would affect everyone uniformly. Some teams found some help when changing vexnet keys out. All the bots that shut down did it in the same manner you have described.