Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /home/dwtechco/public_html/vendor/zikula/coreinstaller-bundle/Event/CoreInstallerBundleEvent.php:18 Stack trace: #0 {main} thrown in /home/dwtechco/public_html/vendor/zikula/coreinstaller-bundle/Event/CoreInstallerBundleEvent.php on line 18