The wiki needs to be updated to a more modern version of MediaWiki. Per [wiki]Special:Version[/wiki], the version that is currently used is the LTS branch that was discontinued in June. You need to upgrade to the 1.22 (or, if you're feeling like doing a couple manual changes, 1.23) branch.
If there was a github repo with the wiki on it I would make a pull request, but it looks like it's not on the main github repo for the website.
Sorry, amazing game, but that's a pet peeve of mine and it's always the first thing I check on.
Wiki is out of date
Re: Wiki is out of date
To cut down on maintenance, we're using the distro packages, so we're stuck with that version until sometime in 2015 (Debian jessie freezes at the beginning of November; typical time from freeze to release is 6 months).
(from the post title, I was *sure* the answer was "it's a wiki, you edit it" but I guess I was wrong)
(from the post title, I was *sure* the answer was "it's a wiki, you edit it" but I guess I was wrong)
Former programmer for the TMWA server.