WordPress辅助菜单中的无效菜单项

Question

Wordpress管理员外观侧显示辅助菜单中的无效菜单项。我正在child theme和custom post type工作。请查看我的代码以获取自定义帖子类型，并查看代码以注册辅助菜单。

    //Register Post Type
    add_action('init', 'portfolio_register');

    function portfolio_register() {

        $labels = array(
            'name' => _x('portfolio', 'post type general name'),
            'singular_name' => _x('Portfolio Item', 'post type singular name'),
            'add_new' => _x('Add New', 'portfolio item'),
            'add_new_item' => __('Add New Portfolio Item'),
            'edit_item' => __('Edit Portfolio Item'),
            'new_item' => __('New Portfolio Item'),
            'view_item' => __('View Portfolio Item'),
            'search_items' => __('Search Portfolio'),
            'not_found' =>  __('Nothing found'),
            'not_found_in_trash' => __('Nothing found in Trash'),
            'parent_item_colon' => ''
        );

        $args = array(
            'labels' => $labels,
            'public' => true,
            'publicly_queryable' => true,
            'show_ui' => true,
            'query_var' => true,
            'menu_icon' => get_stylesheet_directory_uri() . '/article16.png',
            'rewrite' => true,
            'capability_type' => 'post',
            'hierarchical' => false,
            'menu_position' => null,
            'supports' => array('title','editor','thumbnail')
          ); 

        register_post_type( 'portfolio' , $args );
    }

    register_taxonomy("Skills", array("portfolio"), array("hierarchical" => true, "label" => "Skills", "singular_label" => "Skill", "rewrite" => true));


register_nav_menus(array(
    'primary' => 'Primary Menu',
    'secondary' => 'Secondary Menu',
));

有关问题，请参见