I normally fly out in the country where I live. I have flown at parks or base ball fields also. Today I Happened to make it out to one of the major cities and I wanted to get some video of the skyline of the town. I picked an open parking lot with not much around it but a street lamp here or there. I calibrated the compass twice just to double check and both times it looked good. I flew around a few rounds. Then brought it back over head of me but up about 500ft in a hover. I went to look at my monitor and check a few things before I continued. I looked up and gave it stick input to move forward and it wouldn't move. It wouldn't do anything. I watched it and realized that its gone into fail-safe mode and is coming down to land. The transmitter was still on. I had not flipped a switch to fail-safe it. So I flipped the S1 switch and flew it around a little but just gradually kept bringing it down. Then The Red Yellow Red Yellow was flashing on the lights. Thats compass error I believe isn't it? When it took off it was fine. But then it fail safed and then compass error. Im a little worried. I just updated all the firmware and software over the weekend.