User blog comment:Rappy 4187/Technical Update: March 10, 2015/@comment-452-20150312181303/@comment-26009167-20150313195604

@452: No specific chat - the bug is happening on all wikis. Thus, to prevent inconveniencing other wikis, I'm doing the tests on my own personal wiki, w:c:michi-test.

Currently I'm trying to narrow down what could be. It seems to be related to a chat script added in Chat.js, however I'm going to go through the list and see if any specific script is what's causing it. I'm going to not only report what script seems to be causing it in my email, but I will also contact the creator of the script. It's possible that it could be on Wikia's side since this didn't happen before this update, and it's possible the script creator didn't plan for this.

If you wanna test it out, then feel free to copy over the chat.js from my wiki: w:c:michi-test:MediaWiki:Chat.js