WebM videos are served with a wrong MIME type. It's always the following:

Content-Type: audio/webm

For videos this should be:

Content-Type: video/webm

See http://www.webmproject.org/docs/container/ for more information.

It seems to be no problem inside the html video tag, but there are programs which don't show the video if the content-type is "audio/webm" and the file is called directly.

Version: wmf-deployment
Severity: normal