I have a duplex Otis 411. We have a car that when the world tool is plugged in , it wont see any of the boards. we replaced all boards and software chips etc. We still have the same issue. I can take all the boards and move the problem to the other car. Safety circuit (C) is out but all circuits are good. Has anybody experienced such a issue?

It was bad software.

Thank you for taking the time to post what it was. So nice to get to hear what it was.