Help! -No License Key

[Zargen]

So I just got the game off of Amazon. Downloaded; installed the uber patch. And finally I go to try and play it. And then I get an "Install License" pop up before the game even starts. And I dont know what to do! It says a key should be on the manual for the game. But from what I've seen(looked it over front to back) There is no Key for it. So really; I'm a bit PO'ed and wondering if I got screwed over somehow on this. Am I missing something obvious? Or did I buy a game that didn't come with everything?