Hi, While flying today, my Phantom 4 went from hovering to flying in somewhat fast and erratic, wide circles, bank heavily as it flew. It really took me by surprise because it's been rock solid up until now. The winds on the ground were calm, but I was flying close to 300 feet so it's possible there were gusts. Here's a link to Healthy Drones: HealthyDrones.com - Innovative flight data analysis that matters You can see at about 5:39 minutes without touching the control, the Phantom starts to take off in a curved path accelerating to about 15 mph before I realize something is wrong. I was able to bring it down and regain control but it did not want to hover. I then brought it back to me and was able to hover low to the ground. Then I lifted it to about 60ft above me when it began the same behavior. So I called it a day. There were no indications of trouble in the app - good GPS, good signal, etc. but when I got it on the ground it started reporting a "Vision System Error (f00000) I chatted with DJI tech and we went through all the IMU, controller calibration. The error is gone, but I've lost a little confidence in the machine. Any idea what went wrong? I would really like to understand this because it would be been a crash had I been in a less open area and I badly don't want it to happen again. Thanks.