Take a look at [this line of code](https://github.com/linkeddata/ldphp/blob/ca335aa26ba431d192066a55ef49478f1b6f779a/www/inc/header.php#L39), it seems that the `reflibjs` link is broken now. After checking the `rdflibjs` [repository](https://github.com/linkeddata/rdflib.js/), it should build the `dist` folder for own server now.