That demo works for me. The total errors I get when reloading a page are:
window.controllers is deprecated. Do not use it for UA detection. http
+s-everywhere.js:335
GET https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.2/highl%C2%A
+Dight.min.js [HTTP/1.1 404 Not Found 24ms]
GET https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.2/highl%C2%A
+Dight.min.js [HTTP/1.1 404 Not Found 24ms]
ReferenceError: hljs is not defined pm2.js:153
A call to document.write() from an asynchronously-loaded external scri
+pt was ignored. direct_link_selflink.js:1