I've been trying to install MWC on my wiki (http://en.starbricks.t15.org/) and I've encounter a couple of problems.
First, I installed the extension and then ran update.php from MaintenanceShell. I could get to any page, and the Special:Chat was displaying only an inputbox.
Then I tried running .sql files for phpMyAdmin, and the chat page looked normal.... but still coudlnt submit a message or look at any pages.
I'm using MediaWiki 1.22.6.