Fatal error: Uncaught Error: Class 'Symfony\Component\VarDumper\Cloner\Stub' not found in /home/app/htdocs/message_gateway/vendor/symfony/var-dumper/Caster/TraceStub.php:21 Stack trace: #0 {main} thrown in /home/app/htdocs/message_gateway/vendor/symfony/var-dumper/Caster/TraceStub.php on line 21