My iTunes keeps shutting down every time I try to play video. Even in safe mode.

iTunes stops working and turns off every time I click on one of my downloaded videos. For years I have had no problems, now all of a sudden I am having this problem. It seems to be connected to the last update I got. Maybe it is connected to some plug-in that didn't take correctly. I don't know. And I don't know where to start. I am not very tech savvy. I need a teenager at home again to figure this stuff out for me. But, they all flew away from the nest.