Error: "Currently the option to add a moderator to a page is only available in the Main Namespace. We would also like to be able to add moderators to pages in the namespaces."
Solution: "to add responsible feature on another namespace please do the following steps: index.php?title=Spezial:Wiki_Admin&mode=Preferences -> Responsible editors -> In List "Enabled namespaces" select all entries as needed, save to apply."