Maximum Number of Teams in Tournament Issue (FM16 Editor)

I'm having a real issue with the FM2016 Editor. I want to set the amount of teams in the FA Cup to 1006, but for some reason it won't let me have any more than 512 teams, no matter what I do. Is there any way to actually bypass this, or is this just a glitch that basically means the Editor is useless to me?

Any help would be greatly appreciated.

EDIT: Problem resolved. If a moderator could lock this, that would be fantastic.