I find this deplorable that you purchase videos from ITunes and can't play them. You have to force your application to work with a 32 bit process.
I tried this, ITunes said I had to reauthorize my computer. Understand the technical reasons, as I'm in IT myself. However, this needs to be resolved. I've got several videos/movies/TV etc that have this issue, and have to open them in Finder, then right click and watch them in the QuickTime app. These videos are not old, they are part of an ongoing season, downloaded via Season Pass.
When you move the files to another location and reimport or delete them and redownload, the issue is resolved.
Fix the issue Apple.