Board Thread:General Coding Help/@comment-5961377-20160417062549/@comment-24473195-20160513214702

Gameuser10 wrote: load.php?lang=en&mode=articles&articles=MediaWiki%3AChat.js|User%3AGameuser10%2Fchat.js&only=scripts:5 Uncaught ReferenceError: mainRoom is not defined

Google Chrome. Based on that output, you seem to be loading Chat.js twice. One is the Wiki's chat.js and the other is your personal javascript. It is likely that they may be interfering with each other.