picture quota exceed? -____-"

i felt like want to change something about my blog,

maybe change picture layout or anything,

suddenly when i want to actually post a picture for my layout, 

it came out like this:

PICTURE QUOTA EXCEED? 

what is that, please someone explain it to me. -_____-"

and now i can't change my profile picture, can't change my banner, can't put pictures for my layout.

how it's this happening?

i don't remember about blog have this quota picture rules or anything. urghhhh.