Notice: Use of undefined constant ABSPATH - assumed 'ABSPATH' in X:\wordpress\Nieuwe map\wp-admin\includes\nav-menu.php on line 11

Warning: require_once(ABSPATHwp-admin/includes/class-walker-nav-menu-edit.php): failed to open stream: No such file or directory in X:\wordpress\Nieuwe map\wp-admin\includes\nav-menu.php on line 11

Fatal error: require_once(): Failed opening required 'ABSPATHwp-admin/includes/class-walker-nav-menu-edit.php' (include_path='.;C:\php\pear') in X:\wordpress\Nieuwe map\wp-admin\includes\nav-menu.php on line 11