Can't use art brush or scatter brush in illustrator

So I clicked on the brushes panel and could not see the scatter brush or the art brush. I clicked on the little "add" button, but they both won't let me click on them (pictured). Can someone please help me with this problem? I am new to illustrator and this does not seem like a recurring theme for everyone (I've looked on other forums as well and no one seems to be having this problem).