I have the app via Microsoft and it says I am updated to the latest version. However, no matter what I do, just about every time I use the program and try to change a video speed to .3 or slower, it crashes. It doesn’t matter what video I put in it or if I try to change it to .6 speed and then to .2, etc. It changes to .5 and all fine. It just won’t change to the slower speed without crashing. Sometimes it will work after I try it 8-10 times of reloading the program and file.
Some video formats do not handle the speed change well. You can try using Properties > Convert and then change the converted file’s speed.