Fatal error: Uncaught Error: Class "WP_Customize_Section" not found in /var/www/vhosts/awxpokmt.host213.checkdomain.de/htdocs/playground/wordpress/wp-includes/customize/class-wp-customize-nav-menu-section.php:19 Stack trace: #0 {main} thrown in /var/www/vhosts/awxpokmt.host213.checkdomain.de/htdocs/playground/wordpress/wp-includes/customize/class-wp-customize-nav-menu-section.php on line 19