I have a YouTube channel, and I am trying to make it a lot better by actually editing my videos. I am trying to at least make a channel trailer by stringing multiple recorded videos that I have. However, every time I try to open a video inside of Windows Movie Maker, it shows up as a black screen and lasts for 7 seconds, no matter what video I open. I use Windows 10, and my computer doesn't have bad specs. It would help to get some info on what to do. Thanks.