Vertigo.. this is quite complicated. There can be many things wrong.
Maybe you just need to run a few commands (as Frederick Cheung typed)
to get it to run. But that depends on the site's setup. If you don't
know how they did it, then you'd be shooting at the dark, especially
if you don't know RoR
I would hunt down the ones that used to maintain, and get a hold of
the documentation (pray that there is).