The error you receive deals with the fact that you've downloaded a video which has been encoded with a fake codec. The codec does not exist and it's not a codec actually. More likely, it's an embedded trojan. I advise you should not download it and, instead, obtain a new copy of the video file which won't require a specific codec. These situations happen a lot on the Internet and this is a major cause of malware spreading with this method. The file you downloaded is fake and you should delete it as soon as possible because you can't use it or play it in any player.