The easiest way to test this is to remove the section of code that implements the core_userlist_provider. \core_privacy\local\request\core_userlist_provider, // comment out this line Go the the Plugin privacy compliance registry. "Site administration > Users > Privacy and policies > Plugin privacy registry" Search for the plugin that you edited. Ensure that there is a badge with the text "No userlist provider" next to it. Check that there is no badge next a plugin that should have one (hopefully they are all done).