I recently downloaded the standalone version of lr 6 on my windows 7 pc. I have been using lightroom since version 3 and the upgrade to ver 6 was from lr 5.7. I have never used the slide show module in previous versions. I created several small, 10 - 12 images, slide shows and they play great in lr. However, when I click on the export video it literally takes 5 plus hours to export a small mp4 slideshow to whatever folder I selected. After the export finally completed I was able to transfer them to my ios devices, play them, and also mirrown them on my apple tv.