Fatal error: Uncaught Error: Class 'Symfony\Component\VarDumper\Caster\ConstStub' not found in /home/app/htdocs/message_gateway/vendor/symfony/var-dumper/Caster/LinkStub.php:19 Stack trace: #0 {main} thrown in /home/app/htdocs/message_gateway/vendor/symfony/var-dumper/Caster/LinkStub.php on line 19