User blog comment:Rupert Giles/Global Navigation Update/@comment-17082236-20141204205809/@comment-5558012-20141205035455

Where are you adding this code? A quick search shows you haven't created a js or css page on this wiki. Global.js and Global.css pages only work when created on this wiki. Additionally, (if you did) you can't change the nav back site-wide (MediaWiki:Common.js/MediaWiki:Common.css or MediaWiki:Wikia.js/MediaWiki:Wikia.css).

Edit: Yep, here is your problem. Move the contents of the page to here.