I'm only guessing here, but I'd say you have corrupted the naza firmware when it disconnected . . . .
Try running the update again and see if it connects up to the software etc, make sure you have all controls working and responding as they should, and if all at goes well, try flying again.
If there is an issue, you may need to contact DJI, I'm guessing they have delt with corrupted firmwares before, but weather it can be fixed or not is a different story.
I come from a hobby of car ECU re-flashing, basically changing the firmware of the cars ECU. When ever there is data flow between the car and laptop, touching the cables or plugs is a big NO NO! If anything goes wrong with the flash process, the car is practically useless, and can only be revived thru a factory dealership (generally for around $1000~2000)