The tested stream has no audio. With the current version of the Viblast Player an extra argument should be passed in order to handle this case:
data-viblast-audio="false".
With the next release - expected at the end of this week the player will be able to automatically handle audio only and video only streams.
Vladislav
<html>
<head>
<script type="text/javascript" src="https://cdn.viblast.com/vb/stable/viblast.js"></script>
</head>
<body>
<video
controls
height="400"
width="550"
src="//h4ahsm.vkcache.com/hls-vod-s7/flv/api/files/videos/2017/01/26/14854197157mwnl.mp4.m3u8"
data-viblast-key="759ee919-9a1c-4e40-8792-fbfe27c3f071"
data-viblast-enable-pdn="true"
autoplay
>
</video>
</body>
</html>