If the screen started malfunctioning while you were watching a video, perhaps the video card’s driver may need updating. This can be done in the Device Manager utility (devmgmt.msc).
However, just in case I’m wrong, please run your computer’s video troubleshooting utility. This can be found in your computer’s Settings at Settings > Update and Security > Troubleshoot > Video Playback. Be sure that you choose the “I want to continue with this troubleshooter” option at the bottom when the utility’s window opens.