What is the strangest issue with a robot you have ever seen?

[dmelcer9]

So last year, our lifting mechanism for the totes kept twitching up and down. This would happen whenever the bot was enabled, even when the controller wasn't connected. We calibrated the motor controller, but that didn't fix it. We went through the lifter code line by line and there was nothing there that could have caused the twitching. To this day, we still don't know what caused the twitching, but it doesn't matter because we cannibalized the control system for our 2016 bot .