title: IE 11 not playing MP4 Video ("Invalid source")
body: <p>I am currently working on a web project where I have to play multiple videos (all mp4). </p>
  
  <p>The "funny" thing about it: every video plays in IE11 apart from one.
  IE returns the error: Invalid Source.</p>
  
  <p>Now you probably think that the video which is not playing differs from the others. But actually it doesn't. I rendered all videos with the same settings from After Effects via Adobes Media Encoder with H.264 Codec.</p>
  
  <p>Any suggestions?</p>