Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\EventListener\AbstractSessionListener" not found in C:\WebServer\htdocs\bookshelf\vendor\symfony\http-kernel\EventListener\SessionListener.php:24 Stack trace: #0 {main} thrown in C:\WebServer\htdocs\bookshelf\vendor\symfony\http-kernel\EventListener\SessionListener.php on line 24