Fatal error: Class 'Symfony\Component\EventDispatcher\Event' not found in /var/www/html/dev/spa/vendor/symfony/event-dispatcher/Symfony/Component/EventDispatcher/GenericEvent.php on line 21

Call Stack:
    0.0007     251216   1. {main}() /var/www/html/dev/spa/vendor/symfony/event-dispatcher/Symfony/Component/EventDispatcher/GenericEvent.php:0