Fatal error: Uncaught Error: Class "JMS\Serializer\AbstractVisitor" not found in /home/activeexcavators/public_html/vendor copy/jms/serializer/src/XmlSerializationVisitor.php:18 Stack trace: #0 {main} thrown in /home/activeexcavators/public_html/vendor copy/jms/serializer/src/XmlSerializationVisitor.php on line 18