I created a new article and set it to the demo category I created during the video tutorial.
So I have a menu item - list & search, when I visit that page I can see the categories I created.
But if I click on a category title, the one where I put my article, there's no article in the category.
Actually for some reason, every category title I click on has this message on the category page
Template Style does not exist. Open the Content Type & save it again. (Intro + Content views)