You are in Closed Caption mode. One that is not usually used. On your remote, if there isn't a button marked "CC" then go into the menu and find the caption mode and turn it off.
Your TV is in closed captioned mode. You are not in one of the Text modes, but in one of the modes that will fill the screen with a big black box and if this mode were used on that network, you would have text in it. Of course it goes away every time you … Read more