Thread:Extension talk:Lockdown/How to prevent access to Login/signup page?/reply (3)

If you include ConfirmAccount as very last thing in your LocalSettings.php, there should be no need of $wgGroupPermissions['*']['createaccount'] = false; because ConfirmAccount sets this on its own. If you have other extensions or core configuration settings after ConfirmAccount, then they might be overriding this setting.