Having recently upgraded my P3 advanced to the latest Firmware_v1.3.20_en I tried to upgrade the rc using the usb but to no avail. I have since inadvertently upgraded to the latest DJIGo app on my Ipad and now I have a message which states rc upgrade required. I have again tried to update with the usb as the app says I can't do it through the app but still it won't update. Don't want to fly it until the rc is updated. Any ideas?