Why can't I replay the Fnord level in Peggle Blast?

//ads -- adsterra.com -- native banner
?>
I'm trying to unlock one of the achievements in Peggle 2 related to finding all of the secret pegs. However, I can't access the last level with Fnord. Every time I click on it, it says: "Not a good idea... It'd be best not to give Fnord another chance to betray us".
Are there some prerequisites to being able to play this level again, or are you only able to play this level once? There doesn't seem to be any DLC related to it either.
Pictures about "Why can't I replay the Fnord level in Peggle Blast?"



Liz Phair - Why Can't I? (Official Video)
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: cottonbro, Mnz, Kelly, Tima Miroshnichenko