pyroevil on "How to edit content of category page"

Hi,

I use wordpress 3.8.1 with the theme tweenty fourteen. Unfortunetly , when you click on a category with no post assigned to it for now , it's display a "not found" page. I try to make a plugins with hook that replace that by a text ( like the description of the category ). If no post is in the category , only description is displayed , if category have post , description is displayed and posts founds after.