Hi pas255,
Thanks for reaching out to Apple Support Communities. It sounds like iTunes is not playing any video. We’ll be happy to help with this. Take a look at the info under, ‘If you can’t see your video playing’ from the following link for info on how to resolve this: Play movies and other video in iTunes on PC
If that doesn’t help, quit iTunes and restart your computer. Test again and see if that helps. You may want to make sure iTunes is up to date as well: Update to the latest version of iTunes
Does this happen with just this one video or multiple videos? In addition to the videos, any pattern of specific file formats? If this seems to happen with multiple videos and uninstalling and reinstalling iTunes does not help, reach out to Apple Support at the following link so they can continue to look into this with you: Apple Support
Thanks for using Apple Support Communities.