Fatal error: Uncaught Error: Class "WP_REST_Controller" not found in /home/www/act.com.cy/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php:16 Stack trace: #0 {main} thrown in /home/www/act.com.cy/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php on line 16