User blog comment:DaNASCAT/Technical Update: November 22, 2011/@comment-13301-20111129102035

If the javascript file served from the domain connect.facebook.net is not loaded properly, because it's down or something it's blocking access to facebook (enterprise/school proxy, adblock or whatever) there are some javascript that fails to load, like for example TabView and Slideshow Galleries.

Wikia shouldn't depend on failbook for loading their JS properly.