Trying to boot up Symfony app 3.4 with php 7.3 throws an exception:
Fatal error: Uncaught LogicException: The cache must return instances of ClassMetadata, but got 1. in /var/www/contoso/vendor/jms/metadata/src/Metadata/MetadataFactory.php:73 Stack trace:
.0 /var/www/contoso/vendor/jms/security-extra-bundle/Security/Authorization/Interception/SecurityPointcut.php(84): Metadata\MetadataFactory->getMetadataForClass('AppBundle\Contr...')
.1 /var/www/contoso/vendor/jms/aop-bundle/DependencyInjection/Compiler/PointcutMatchingPass.php(149): JMS\SecurityExtraBundle\Security\Authorization\Interception\SecurityPointcut->matchesMethod(Object(ReflectionMethod))
.2 /var/www/contoso/vendor/jms/aop-bundle/DependencyInjection/Compiler/PointcutMatchingPass.php(65): JMS\AopBundle\DependencyInjection\Compiler\PointcutMatchingPass->processDefinition(Object(Symfony\Component\DependencyInjection\Definition), Array, Array)
.3 /var/www/contoso/vendor/symfony/symfony/src/Sy in /var/www/contoso/vendor/jms/metadata/src/Metadata/MetadataFactory.php on line 73
I Changed the file permissions with chmod 777 to the app/cache and app/logs folder but is not working.