PHP:
Fatal error: Uncaught Error: Class "WP_REST_Controller" not found in /www/habi.gna.ch/doc/wp-includes/rest-api/endpoints/class-wp-rest-settings-controller.php:17 Stack trace: #0 {main} thrown in /www/habi.gna.ch/doc/wp-includes/rest-api/endpoints/class-wp-rest-settings-controller.php on line 17