WHY THE HELL ARE YOU TRYING TO DOWNGRADE YOUR SYSTEM MENU!?
Are you deliberately trying to frick it up? Because that's how you brick your Wii!
There's no reason for you to be doing that!
Seriously, explain to me what you're trying to accomplish by downgrading your system menu, and I'll be happy to point you to a better way than that to do it.
From my perspective--that of an avid homebrew user who surely knows a red flag when they see it--you have no idea what you're doing and the error is actually trying to prevent you from making a bad, potentially permanent mistake.