1) First confirm all the existing 7 bulk actions to confirm they still work, eg /admin/user/user_bulk.php Add some users Send 'Send a message' as the action Add test message You only need to confirm that you've correctly gotten to the actual bulk action page, the actions themselves have not changed.   2) Now test adding a new custom action in a plugin /admin/tool/policy/lib.php function tool_policy_bulk_user_actions() { return [ 'tool_policy_reset_policy' => new action_link( new moodle_url( '/admin/tool/policy/do_something.php' ), 'Reset policy' ), ]; }  3) Purge caches php admin/cli/purge_caches.php 4) Now reload the bulk actions page and check that there is an additional action ("With selected users...") of "Reset policy": /admin/user/user_bulk.php 5) Select it. You should go to the url which doesn't exist but that's expected. /admin/tool/policy/do_something.php