Declaration of UsersController::beforeFilter() should be compatible with AppController::beforeFilter(Cake\Event\Event $event)
The solution is to add the following line to UsersController.php
use Cake\Event\Event;
The cake baked version does not have the above line.
On Cake 4.0.2 Strawberry - it is now -
use Cake\Event\EventInterface;
public function beforeFilter(EventInterface $event)
{
parent::beforeFilter($event);
}