Please take a look at the below link, change the setting, then restart MediaHome and try again:

What should I do if there is pixelated playback, black screen or A/V sync problem

If the problem still occurs, please change another setting by following the steps in the below link:

What should I do if MediaHome plays DVD or video files without image

If above solutions cannot resolve the problem, please check if your PC/Laptop has two graphics cards, usually an integrated graphics card and a discrete graphics card.

If yes, please switch the graphics card to another one, then play DVD again.