Fatal error: Uncaught Error: Class 'WP_REST_Controller' not found in /home/crossfir/public_html/wp-includes/rest-api/endpoints/class-wp-rest-widget-types-controller.php:17 Stack trace: #0 {main} thrown in /home/crossfir/public_html/wp-includes/rest-api/endpoints/class-wp-rest-widget-types-controller.php on line 17