Fatal error: Uncaught Error: Class "Symfony\Component\HttpFoundation\HeaderBag" not found in C:\www\Apache24\htdocs\agenda-dif\vendor\symfony\http-foundation\ResponseHeaderBag.php:19 Stack trace: #0 {main} thrown in C:\www\Apache24\htdocs\agenda-dif\vendor\symfony\http-foundation\ResponseHeaderBag.php on line 19