Humble have announced (link below) that Steam have removed support for the 0Auth system that automated the process of redeeming Steam keys. So Humble are going back to the old way of manually redeeming keys. They do not say why support for 0Auth has been removed in their announcement. Does anyone else know why this has happened? I thought one of the reasons they stopped using the old manual method was because of people selling on the Steam keys at a profit. So it seems odd that they are going back to this method.

http://blog.humblebundle.com/post/107906804069/changes-in-steam-key-redemption

Weird. I don't really care either way but clicking a button was slightly more convenient than copy pasting a key.

So Valve's decision forced their hand. Valve works in mysterious ways.