Flying P3P December 25. I had a yellow warning in upper left of screen, "Ultra Sonic systems failure; Land Immediately" Has anyone heard of this? I have done forum thread searches with no results. My drone remained under control th whole time th message was displayed. l was able to bring it safely back & down to land near my feet with no other issues, battery at 56% when message appeared & 40% when l shut it down. After recharging that battery I powered up th drone for a while tethered at home no repeat of message. Did l interfere with th Archangel & his gang? Is it possible that there are directable interference systems for disabling drones in flight? Have l been reading too many cheap newspapers? I don't think it is drink related as l have been teetotal since 1988. Any way, Best Wishes to all of you for th New Year.