Users can't buy from shop

A little red asterisk shows up and in the chat it just says "Can't buy this item". I've changed a lot of settings and nothing seems to work. It even does it to me as well for certain items as admin.

These items are based on paid items from paid DLCs, which, under the new rules, are prohibited from being granted to players if they have not been purchased, regardless of whether they have skins or not. If such items are granted to players without permission, the server may receive a ban in search results. You may remove the DLC-checking plugin at your own risk