WordPress - 致命错误：在第106行的C：\ inetpub \ wwwroot \ wp-includes \ class-wp-widget-factory.php中找不到类'WP_Widget_Tag_Cloud'

suddenly getting this error

Fatal error: Class 'WP_Widget_Tag_Cloud' not found in class-wp-widget-factory.php on line 106

No changes at all. Deactivated all plugins and changed themes and still this error

public function register( $widget ) {
        if ( $widget instanceof WP_Widget ) {
            $this->widgets[ $this->hash_object( $widget ) ] = $widget;
        } else {
            $this->widgets[ $widget ] = new $widget(); // LINE 106
        }
    }

Any ideas?

Also now getting

Fatal error: Class 'Vc_Role_Access_Controller' not found in wp-content\plugins\js_composer\include\classes\core\access\class-vc-current-user-access-controller.php on line 7