I am trying to create a DVD using pictures, video, and audio. Everything works fine until I addd my video. After I add the video it says that all missing files must be resolved before editing the production. I search for missing files and it say there are none. The video I am adding came from a dvd that I copied to my computer.

Did you go to Windows Explorer and in tools, options set to 'show hidden files and folders'? There may be hidden files on the DVD that weren't copied

Again, if this was a commercial DVD, it is almost certain to be copy protected and can't BE copied by any commercial app