Sorry for the necrobump, but how exactly did you get the perfect 31 IV Latios to work in PKHex? I see the screenshot above, but did you just want that the HP to be 31 IV and nothing else?
I'm trying to get basically a perfect 31 IV across the board and even if I'm editing the southern island one I'm still getting that same error. I've tried everything I can find and having absolutely no luck