add this method (if it's not exists) in qa-theme.php or in a layer plugin:
public function initialize()
{
if ($this->template === 'user' && qa_get_logged_in_level() < QA_USER_LEVEL_SUPER){
$this->content = qa_content_prepare();
$this->content['error'] = qa_lang_html('users/no_permission');
}
qa_html_theme_base::initialize();
}