Fatal error: Uncaught Error: Class 'Metadata\MergeableClassMetadata' not found in /home/lafaamicps/www/symfony/vendor/jms/serializer/src/JMS/Serializer/Metadata/ClassMetadata.php:32 Stack trace: #0 {main} thrown in /home/lafaamicps/www/symfony/vendor/jms/serializer/src/JMS/Serializer/Metadata/ClassMetadata.php on line 32