I had this exact problem and I narrowed it down to engine prime transferring rekordbox data to usb device. I fixed it by preparing the drive in rekordbox, then putting in the stick in my prime go and let it import the playlists. I then took the usb out and put it back into engine prime and analyzed the songs on the stick, then I had no problems after. Seems like the problem was engine prime reading exported rekordbox xml.