How to change my signature?

[Kazar]

This happened to me before, sorry if there's an obvious answer or something, but how do I change my signature? I go to the about me section on my profile and while everything else allows me to write in it, the signature won't let me. How can I change it? This happened to me before, it wouldn't let me write a signature, and somehow it fixed itself, but I don't know.

[Kazar]

LOL never mind i got it.