LR6 crashes every time I press Preview or Play in the Slide Show Module. GPU accel. is off. LR4.4 works as expected with the same photos. It starts to prepare slides for preview and seems to crash after the last slide is prepared. It also is so fast in the beginning of preparing slides that I can't see where it begins but slows considerably around slide #50 or so and then continues one slide at a time until the last slide and then crashes.