Error during playback

i use the Ixpand to play backing tracks in music lessons. I can play something then maybe nothing else for 15min during which time my iPad is idle. The next track I go to play often comes up with an error dialogue box telling me to check the log as it can’t open my selection. Any clues? I tend to have to fumble around and restart the drive all over again which is awkward. And how do I check the log? Nothing seems obvious when I look at the menu or settings.