I think it's a bug with the recent versions of Clappr (and for mp4/local files).

If you click on the video once and reload the page, autoplay may work.

In any case, AllVideos v5 is coming in the next few days and will use native browser media playback, so this won't be an issue any longer.

"If you click on the video once and reload the page, autoplay may work."

Try in Chrome with a private window and you'll see that what I said checks out.

Other media types may work but they are not native and will be simply linked when the new version comes out.