Wprdpress Feed is not loaded

[miau]

Hi, I am trying to use the Player with wordpress (latest). I made a category and a post with the link to an audio file. WP offers automatically a Podcast RSS/ATOM of this Category. I would like to use this as playlist, but it says "loading playlist" and does not load. The Manual Playlist works but it is not dynamic.

[miau]

the Feed validated on feedvalidator.org

any suggestions? ideas what else to check?