I'm working off the template: http://webflow.com/template/5614f04a1656d72e1bb1adfa
I tried to delete the collection "Categories" and was able to after removing all blog posts, categories, pages referencing categories, dynamic lists referencing categories, and classes w/in a blog dynamic list that reference categories. As far as I can tell within the app, there are no more references to categories that exist. Yet when in the designer, when I go to the home page (which used to reference categories) I get an error at the top of the page that says "Cannot find peer collection for slug: category". I have no idea what else I can remove for categories.
Additionally, when I try to remove the category link from the blog post settings, I can successfully remove the field from the Blog collection settings, but when I save the collection I get an error "Error: Collection fields: "Post Description", "Category" currently being used in bindings."