Quick message explaining that chat was broken due to chattags; people sent messages and they didn't show on others' ends, people couldn't enter, and the rail was empty or filled with people who had already left. The issue is being resolved currently. Once Wikia's (and your browser's) cache passes the edit, chat will be working again. As I'm posting this the edit was made live, so a simple bypass should do the trick.
The consequence? Chattags are being removed for the time being. Different revisions of the script will be tested on other wikis, and hopefully we will have a safe version back soon.