User blog comment:DaNASCAT/Technical Update: September 20, 2011/@comment-3459498-20110927032345

■We also fixed the "Error communicating with MediaWiki server" message that was appearing on chat for some wikis.

Unfortunately, this problem has not been fixed for http://dota.wikia.com/wiki/Defense_of_the_Ancients_Wiki 's chat, when I use Internet Explorer 8.0.7600.16385.