Fatal error: Uncaught Error: Class 'WP_REST_Controller' not found in /opt/app-root/src/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php:22 Stack trace: #0 {main} thrown in /opt/app-root/src/wp-content/plugins/jetpack/_inc/lib/core-api/wpcom-endpoints/gutenberg-available-extensions.php on line 22