CK2 Registration Key from Steam, correct, but its not showing up in my Games ?

[Castellon]

Not common no, or you would see thousands of threads like this one.
Sorry you encountered an issue, Tech support will look into it for you.

Let me send you a PM maybe we can help speed things up.

 

[Castellon]

There are only 2 versions of CK2 for the PC, the GamersGate version, and all other retailers sell the Steam version.