I am not a programmer, so I am not sure what you mean with “built”. I just used the tab “Extra profile fields” that come with the plugin. And I added them to the bottom of every content posting with the widget “Newsletter”. (And everything worked perfectly fine until the last update of the Newsletter plugin.)
Thanks for the answer Stefano, but I don´t understand. I have nothing called “Public” in the Fields. Now I rebuild everything again, and everything seems to work except this strange, empty dropdown option. I don´t know what “the shortcode generating that list selection has some lists IDs specified” 🙁
