You can fix the issue by following ways... a)Cold boot the TV: With TV Remote, hold the Power button until the TV Power off and Powe ON by itself. When you observe the Samsung Logo on the screen, you can release the button. If the TV is not rebooting by itself, just unplug the TV from a power source and connect it again. b)Software Updates: Your TV will not if any software update is pending. To resolve that go to Menu >>> Support >>> Software Update. Check for the updates and update the TV accordingly.