Purchased game through Humble Bundle, after update needs Serial Key

[saraija]

There is no version 1.7. The Humble Bundle brings (IIRC) at least version 1.2.1. The only update available from the FrictionalGames support page is version 1.2. So, you have officially downgraded your version of Amnesia. If you do not see the Justine button on the launcher, there is likely a work around for that with a certain argument being passed to Amnesia, but my memory fails me here.

I guess I'll try uninstalling/reinstalling; I don't remember seeing the Justine button until after the "update" but I could have just missed it by not looking well enough.