Sorry an error occurred

Cake\Routing\Exception\MissingControllerException: Controller class User could not be found. in /var/www/html/gallery/extend/vendor/cakephp/cakephp/src/Routing/Dispatcher.php:79
Stack trace:
#0 /var/www/html/gallery/extend/webroot/index.php(36): Cake\Routing\Dispatcher->dispatch()
#1 {main}
BARRY 瞑想