Fatal error: Uncaught Error: Class "Symfony\Component\Security\Http\Firewall\AbstractListener" not found in /home/ldt/public_html/canvas/udoit/vendor/symfony/security-http/Firewall/ChannelListener.php:28 Stack trace: #0 {main} thrown in /home/ldt/public_html/canvas/udoit/vendor/symfony/security-http/Firewall/ChannelListener.php on line 28