Comentário oficial
You'll need to look through your collection for any songs that don't show the proper analysis indicators. I was chatting with one of our demo DJs the other day and he was having this exact issue. After narrowing down the tracks within playlists, he found that the songs that were causing the export to stop were missing beatgrid analysis, even though he had done them before, and they all showed the new 3Band waveform.
Please see if you are able to narrow down which tracks are failing, then run a new analysis on only those songs.