The div tag with id="navbarSupportedContent" in the navbar is not closed, which means the page contains invalid HTML (which breaks the page in some cases)

In templates/navbar.html, the div tag with id="navbarSupportedContent" is not closed, which is invalid HTML and can cause some parses to think the entire page is within the navbar. The W3C validator (error 3 and 4 as of writing) points this out, and Firefox also shows that there is invalid HTML (though it only detects what is error 3 in the W3C validator).

Screenshot of broken page