Editing catagories caused error

I was moving some widgets around on my site today to add a category widget on the sidebar. I then noticed that I had a misnamed category so i went to the category page and edited it to change the name.

Once I hit save, I got locked out of my site with a page that says error on it. I looked at the page source to see what is going on, and that is all it says “error” with no other info.

Any ideas?

site is http://quickiosgames.com