Fatal error: Uncaught Error: Class 'Symfony\Component\EventDispatcher\Event' not found in /home/app/htdocs/ninja/vendor/symfony/http-kernel/Event/KernelEvent.php:23
Stack trace:
#0 {main}
thrown in /home/app/htdocs/ninja/vendor/symfony/http-kernel/Event/KernelEvent.php on line 23