Roku TV will not play my MP4 by usb port I get a black screen, video is play underneath...??

When I try to play a MP4 video using a usb port it will load and I can select it.  When it goes to play it... there is a black screen over the video.  If I hit pause, I can see the video.  As soon as I hit play again...it again pops up a black screen.  This is a recent problem.  It worked just fine until the last time updated the video.  What am I doing wrong?