I'm not familiar with that game per se, but in general there is a difference between an "activation code" and a "forum registration code". Paradox-branded games don't need or use activation codes (that is, codes to unlock the game itself) - the exception I'm aware of being Mac versions of Paradox games as written, released and supported by Virtual Programming. But Paradox games do have forum registration codes to allow you access to support forums for your game, these you enter here on the forums in the My Games tab at the top of the page.
So can you clarify please:
- is your game Mac or PC?
- does it specifically ask for an activation code at load or install time?
- where did you buy/download the game?
- is the code you have specifically labelled "activation code" or what? Where did you get it?
- even if you do have an activation code, you ought to have a separate forum registration code which you should enter above
Restricted access until e-mail confirmed
You also need to respond to the confirmation email, that these forums sent to your registered email address.