Which file/template is in charge of taxonomies for custom post types?

There’s a giant diagram on the wordpress documentation showing how it chooses which file to display/load, as you can see here:

http://codex.wordpress.org/images/1/18/Template_Hierarchy.png

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If this doesn’t help, my other suggestion is trying with the ‘_’ removed from the taxonomy name, and to test with the rewrite option removed from your custom post type declaration. In my experience wordpress is fidgetty about type names that add punctuation so I try to keep to a singular word or Camel case. You may have more success with a “genre” taxonomy