The best thing is to reach out to the dev of the card. There are issues with the lit element and maybe even the local files they might be pulling…
var LitElement = LitElement || Object.getPrototypeOf(customElements.get("hui-view"));
if the corresponding bit at the end doesn’t say “hui-view” you can try editing it to say that… and make sure you change the version number in lovelace resources or it won’t load it.
That might make it work. I my case I also had to wrap a file URL to make it work as well.