Help sigs

every time i try to change my sig, or put something in it it says invalid file.

i try to put the code in from this http://onemorelevel.com/game/pocket_emo
but also even from poke plushes

 

khv won't let me change my sig either D:
I put a code in and it effed it up, then I went to go re-enter the code in and for some reason it came up with a blank page right after it. I tried refreshing, a different browser, doing it on Ares. Still didn't work.
It's not the computer, it's khv.