Roku TV showed the opening credits of a DVD and then a menu appeared listing the six programs on the DVD. A bar highlighted the first choice. I was unable to make the bar move down using the down arrow, and when I pressed OK I was unable to select and run the program. All that happened was that a black bar appeared at the bottom of the screen showing the HDMI settings. I checked the system update and my Roku system is up to date. Any suggestions appreciated.