Fatal error: Uncaught Error: Call to undefined function the_custom_header_markup() in X:\wordpress\Nieuwe map\wp-content\themes\twentyseventeen\template-parts\header\header-image.php:15 Stack trace: #0 {main} thrown in X:\wordpress\Nieuwe map\wp-content\themes\twentyseventeen\template-parts\header\header-image.php on line 15