libjass stops working after updating

Question

I am using libjass, it works perfectly the first time I use, but after I update the first time it simply stops working(once in a while it works randomly), to make sure I put a code to not save anything in the cache:

<meta http-equiv="cache-control" content="max-age=0" />
<meta http-equiv="cache-control" content="no-cache" />
<meta http-equiv="expires" content="0" />
<meta http-equiv="expires" content="Tue, 01 Jan 1980 1:00:00 GMT" />
<meta http-equiv="pragma" content="no-cache" />

<video id="video" preload="auto" muted controls style="width: 720px; height: auto">
<source src="./vjs/Ansatsu_Kyoushitsu_2_01_Koisuru-PA-Anbient.mkv" type="video/mp4">
</video>
<link type="text/css" href="/pages/libjass.css" rel="stylesheet">
<script type="text/javascript" src="https://arnavion.github.io/libjass/demo/libjass.js"></script>
<script type="text/javascript">
renderer = null;

var assLoadedPromise = libjass.ASS.fromUrl("./vjs/en.ass");
var video = document.querySelector("#video");
assLoadedPromise.then(function (ass) {
    renderer = new libjass.renderers.DefaultRenderer(video, ass);
});
</script>