I was trying to transfer a legendary sparow from my hunter to my warlock that was not yet through the storyline through the app. It threw a unnamed error in the app and then the sparrow disappeared. it is not in any characters inventory, the vault, or post master. Not a big deal as it was a spare but is a bit concerning when it comes to using the app to transfer other gear. shortly after this occurred my fireteam was kicked out of the mission and returned to orbit with the error code guitar in game. no idea if it is related as the two incidents occured about a min or two appart. I have since used the app to transfer weapons with no issues. perhaps this event is limited to the sparrow slot or the timing before the aforementioned error. Details of sparrow that I can remember: 150 speed, legendary, obtained from eververse bright engrams on lvlup, perk was either shorter cooldowns between summon or improved side boost. Details of mission where error code guitar occured. 3 person fireteam, red legion storyline on IO where you first load on the planet to find Ikora. 2 other members of fireteam had sped on ahead to next loading zone when the sparrow transfer issue occured. shortly after we were all kicked to orbit and fire team broken up. we were able to immediately re group up and proceed without any further incident.