I have tried quite a lot of things e.g. started old files created with FM 3 and FM4, without problems. I had until now no crashes. But there are some points that should be changed:
1.) When I choose in settings, that I want no animation, when I build a new slideshow, then this setting is not respected - this is a bug.
2.) When I choose in settings, that the image in portrait mode should be shown complete, I get my images at any possible zoom factor. This should be corrected. It should be possible, that I can choose, that I will get my images every time at a 100% and not a zoom factor at random.
3.) The time a image is shown in a newly created slide show is set at random. That should be stopped. There should be in the settings a option, where I can define what time I would like to be my standard, when I create a new slide show.
4.) I have also tested several audio snippets.The music is quite nice - but these snippets will have a big impact on your slide show, because they change all time settings that have be done before.