Fatal error: Uncaught Error: Interface "Psr\EventDispatcher\EventDispatcherInterface" not found in /Applications/MAMP/htdocs/fislo/vendor/symfony/event-dispatcher-contracts/EventDispatcherInterface.php:19 Stack trace: #0 {main} thrown in /Applications/MAMP/htdocs/fislo/vendor/symfony/event-dispatcher-contracts/EventDispatcherInterface.php on line 19