Why is my media texture not playing?

Im following a video tutorial, as I am completely new to Unreal Engine, and game development in general

Video Tutorial

This is the video tutorial I am following, and around 2:31 he drags his video texture onto the surface of the TV, but when I do that, the surface just turns black, it doesnt show the video file like in the tutorial… I have done everything in the tutorial exactly as he did, up to that point.

Thanks in advance!