You wouldn’t be able to call .play() right after .load() because the player won’t be finished loading the new file before you are telling it to start playing it. I played around with your code a little bit and I think you will find success if you add this code right after you embed the player (via <script src="//content.jwplatform.com/players/DlkGvQyU-cZPlrtAo.js"></script>):
<script>
var newContentLoaded; function loadNewContent(url) {
newContentLoaded = true;
jwplayer().load({
file: url
});
} jwplayer().on("playlistItem", function() {
if (newContentLoaded) {
jwplayer().play(true);
}
});
</script>
That way, you can change the value for the “onclick” attribute for your thumbnails to call the loadNewContent function, like this: