佈景主題全部無法自訂

佈景主題全部無法自訂，任一主題布景按自訂即出現如下錯誤訊息，請問有無方法恢復正常：
Fatal error: Uncaught exception ‘Exception’ with message ‘Illegal widget setting ID: nav_menu_item[]’ in /home/kunwujia/public_html/wp-includes/customize/class-wp-customize-nav-menu-item-setting.php:182 Stack trace: #0 /home/kunwujia/public_html/wp-includes/class-wp-customize-nav-menus.php(660): WP_Customize_Nav_Menu_Item_Setting->__construct(Object(WP_Customize_Manager), ‘nav_menu_item[]’, Array) #1 [internal function]: WP_Customize_Nav_Menus->customize_register(Object(WP_Customize_Manager)) #2 /home/kunwujia/public_html/wp-includes/class-wp-hook.php(298): call_user_func_array(Array, Array) #3 /home/kunwujia/public_html/wp-includes/class-wp-hook.php(323): WP_Hook->apply_filters(”, Array) #4 /home/kunwujia/public_html/wp-includes/plugin.php(453): WP_Hook->do_action(Array) #5 /home/kunwujia/public_html/wp-includes/class-wp-customize-manager.php(754): do_action(‘customize_regis…’, Object(WP_Customize_Manager)) #6 [internal function]: WP_Customize_Manager->wp_loaded(”) #7 /home/kunwujia/public_html/wp-includes/class-wp-h in /home/kunwujia/public_html/wp-includes/customize/class-wp-customize-nav-menu-item-setting.php on line 182