I tried downgrading my Mavic Pro from v01.04.0100 to v01.03.0400 and when I rebooted my Mavic, it wouldn't connect via USB to DJI Assistant 2, or Dumldore or the RC. I cannot access the Mavic in any way to re-flash the firmware. I tried switching USB cables and switching to another computer running MacOS. Nothing works. Is there anything I can do now?