Q: there are exlamation marks next to some of my films, yet I aren't able to play them, I recently shared from one computer to another and the files are now missing?

"Shared" how, exactly? Exclamation points indicate that iTunes can't find the file for the referenced item. Did you somehow inadvertently delete, move, or rename the files or the folders in which they would reside? You can see where iTunes thinks the files should be by doing a "Get Info" on the film listing in iTunes and looking at the "Where" on the summary page. If the files are missing or have been moved, put them back from where you moved them ore restore them from a backup or the other computer, if you copied them there. If you renamed the files, change the name back.  Regards.