Q: movies not playing properly. movies cut off then itunes closes

my movies are not playing. I tried to watch a couple of different ones that I have purchased. They cut off once they start and then itunes closes itself off. How do i fix this please. Should I uninstall all the itunes and reinstall it again? my itunes is up to date. I have tried to ask for support's help.. it worked for a minute then it quit after.. I am so not happy with anything right now.