Fatal error: Uncaught Error: Class "Symfony\Component\HttpFoundation\Exception\UnexpectedValueException" not found in /home/yrdsb11w3creativ/public_html/yrdsb-board-v1.0.0-alpha/vendor/symfony/http-foundation/Exception/ConflictingHeadersException.php:19 Stack trace: #0 {main} thrown in /home/yrdsb11w3creativ/public_html/yrdsb-board-v1.0.0-alpha/vendor/symfony/http-foundation/Exception/ConflictingHeadersException.php on line 19