Webgl unity build won't play Video

I have used video player to play video, everything works fine in unity but when I build it and run on firefox or any other browser,the video won't play. I have tried different settings and different video formats but nothing seems to work. I don't get any errors.

I have an empty scene with camera and video player, no scripts. Just used video player and used play on awake to play the video. Works fine in playmode but won't work in webgl build.