My slide show will not export to video. After about 5% it stalls and never completes. I am using LR 8.4.1 with Mac OS Mojave. I can export if I remove two videos, totaling about 1 minute. I don't have zoom to fill on, I've shut down LR & touched the filter bar (a youtube recommended fix which didn't fix), built 1:1 previews, moved the videos to the end. Nothing works unless I remove the videos. I need help! And thanks.