problem in file LexikMailerBundle/Doctrine/MetadataListener.php

[ickbinhier]

[RuntimeException]
An error occurred when executing the "'cache:clear --no-warmup'" command:
PHP Fatal error: Uncaught Symfony\Component\Debug\Exception\ContextErrorException: Notice: Undefined index: charset in /var/www/html/vendor/lexik/mailer-bundle/Doctrine/MetadataListener.php:17
Stack trace:
#0 /var/www/html/vendor/symfony/symfony/src/Symfony/Bridge/Doctrine/ContainerAwareEventManager.php(63): Lexik\Bundle\MailerBundle\Doctrine\MetadataListener->loadClassMetadata(Object(Doctrine\ORM\Event\LoadC
lassMetadataEventArgs))
#1 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php(242): Symfony\Bridge\Doctrine\ContainerAwareEventManager->dispatchEvent('loadClassMetada...', Object(Doctrine\ORM\Event
\LoadClassMetadataEventArgs))
#2 /var/www/html/vendor/doctrine/common/lib/Doctrine/Common/Persistence/Mapping/AbstractClassMetadataFactory.php(332): Doctrine\ORM\Mapping\ClassMetadataFactory->doLoadMetadata(Object(Doctrine\ORM\Mapping\C
lassMetadata), NULL, false, Array)
#3 /var/www/html/vendor/doctrine/orm/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php(78): Doctrine\Common\Persistence\Mapping\ in /var/www/html/vendor/lexik/mailer-bundle/Doctrine/MetadataListener.php on
line 17

[lightglitch]

In my case this happens because I have a master/slave configuration.