Hello ... I would love to help but I have the same problem and for days I'm trying to solve.
When I connect the debug board to try to connect but then jumps me an error saying that at this moment is this ejecuntando if I want to stop, when I put it if I said that it was not possible. As I watched I suspect can not estop the board or there is a problem with thereset. You might have accidentally stepped on the IVT?