User blog comment:Dopp/Technical Update: April 26, 2011/@comment-1393830-20110427175825/@comment-1997905-20110427200519

I can confirm that it only occurs when the script receives it's response from the server. Basically, the enhanced changes file is within the WikiaArticle element, which is what AjaxRC loads. The url is interpreted as a local url (a file on your computer), which of course it fails to find, thus throwing an error and terminating the load before the content is registered. The easiest way to fix this is to have the tech people move the enhanced changes file out of WikiaArticle - since most people copy and paste their code and don't use the import, you'll have a hard time tracking down every single wiki with AjaxRC, and fixing the reference. As for the number of people using it, I have no idea - but I do know that mid size to larger wikis have the script in their Common.js, which means as of now there's a notable portion of people who can't view RecentChanges at all.