Flexfile Search returns nothing

I've created some file forms with a variable "category" (a dropdown list) and then created a search definition on "category". The search shows up in the menu as it should, but when I execute a search it says "your search contained no results" eventhough I have files with different category types. Can you tell me what might be going wrong?

Also, is there a way to have the search option show up on the general files page so that you could sort files without leaving the files page?

Form and related plugins

Form and related plugins

User-generated content, flexible user and group profiles, registration forms, custom file forms