Fatal error: Uncaught Error: Class 'WP_REST_Controller' not found in /mnt/volume_lon1_02/home/duncanp/public_html/www2.flightdelayrefund.com/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php:16 Stack trace: #0 {main} thrown in /mnt/volume_lon1_02/home/duncanp/public_html/www2.flightdelayrefund.com/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php on line 16