x9 output style - bibliography template - new reference style


I am using endnote x9 and I am having trouble editing the output style. I would like to add a reference style template at the bibliography section but I cant add anything. 

A few are there already (Journal Article, Book, newspaper article etc.) and I can edit those without problems.

I would like to add more reference style templates now (for example unpublished work) but when I click the dropdown menu at the top where it says reference styles and choose a reference type (unpublished work) nothing happens. I can see the ones that are there already have a little hook but when I click a new one nothing happens.

I hope someone can help.

Thanks a lot!