Board Thread:Support Requests - Getting Technical/@comment-3223616-20130924074723/@comment-4519283-20130927212524

Aha! The problem is that Template:Age in weeks doesn't exist. When you include it as a template, Mediawiki picks up that it doesn't exist and instead links to it, using Template:Age in Weeks. The surrounding is told to evaluate that and doesn't know what to do with it.

I see that you already have a template named Template:Age. I would move the Template:Age in years... to something like Template:Expanded Age to shorten it up.