If it says cell broken I personally wouldn't want to mess with it. Lipos can hurt you. If you want to do ANYTHING with it I would recommend doing it outside or in a garage and stay a safe distance but keep an eye on it. I know it sounds paranoid but unless you want to dispose of it (there is a proper way to do that too) make sure you try to be safe around it. Make the call to DJI yet to see what they say?
Does it stay after a power cycle? I've had that message a few times as well but it was obviously erroneous as a power cycle would clear it, and watching individual cell voltages closely on the subsequent test flight close to ground showed nothing abnormal.