What email address and password are you using? You can't use the ones that you use here because it's not related to the game. You might have to start an account with that email address and password but it won't automatically load the game if you never signed up for a King account before.
If you did sign up for an account prior to this and it's not allowing you in then click on the "forgot password" and they will send you a temporary password to get in.
You could use the same email and password because it's not connected to this community. Yes you have to create a King game account. In here it's the game community account. Two totally different areas.