Video Texture goes Black

Hey Guys,

So i try to make a interactive Screen with some Buttons and every button should show a different Video if clicked.
My Interactive widget Works like it should i can hover over my Buttons and can click them, but the Video part isnt working like intended. I made a Mediaplayer with the Video and a Media Texture out of it and it works atleast in the Editor as soon as i go into the game to look if the video is shown even if i dont bind them to a button and try it for testing porpouses it instantly turns black, my texture is black and my Mediaplayer doesnt contain the video file anymore… is there a different way to get my Videos running or i just f*d up at some point.