My P4 flew just fine until a few weeks ago. I upgraded to the latest firmware (P4, remote and G0 4 app, ios), now my P4 will not fly. It tells me "ready to fly" and the motors start up and go into an idle mode. when I try to launch the drone is unresponsive - it just sits there with the motors idling. I get no indication on the GO app of any problem. I am a photographer and am attempting to fly commercially. (Just got my FAA license). Thankfully I have no aerial jobs the next few weeks. Not sure how to approach this other than contacting DJI. Glad I found this forum, you all have a lot of great insight into these things.