phantom 4 lost

I can't believe I lost my drone today. I was flying about 1200 feet away and 158 feet in the air. I could see the lights. I received a lost connection aircraft message then the whole app went gray( same when the transmitter is turned off and not connected to the aircraft). This wasn't a big deal...

Hi, Im a video designer and a newbie in the drone world, so sorry for my lack of knowledge. I was flying my p4 all the day long up on forests and mountains without any problems, no big interferences, gps was ok but at some point , when he was out of sight, the aircraft disconnected and the...