Hi "Are you using the trunk version of the Drools Server project?" I'm using drools-server 5.0.1 "can you share with us the messages that you are sending to the server?" <knowledgebase-request> <globals/> <inOutFacts> <named-fact> <id>test</id> <fact class="test.Test"> <date>2009-09-27T11:59:00.000Z</date> </fact> </named-fact> </inOutFacts> </knowledgebase-request> This xml is marshalled from a jaxb generated pojo, when the java code looks like this: package test; import javax.xml.bind.annotation.XmlAccessType; import javax.xml.bind.annotation.XmlAccessorType; import javax.xml.bind.annotation.XmlElement; import javax.xml.bind.annotation.XmlRootElement; import javax.xml.bind.annotation.XmlSchemaType; import javax.xml.bind.annotation.XmlType; import javax.xml.datatype.XMLGregorianCalendar; @XmlAccessorType(XmlAccessType.FIELD) @XmlType(name = "", propOrder = { "date" }) @XmlRootElement(name = "Test") public class Test { @XmlElement(required = true) @XmlSchemaType(name = "dateTime") protected XMLGregorianCalendar date; public XMLGregorianCalendar getDate() { return date; } public void setDate(XMLGregorianCalendar value) { this.date = value; } } If I comment out the <date> element in the above xml then I get a normal reply: <knowledgebase-response> <globals/> <inOutFacts> <named-fact> <id>test</id> <fact class="test.Test"/> </named-fact> </inOutFacts> </knowledgebase-response> The jars for the java class are in the drools-server lib and I've put the jaxb-api.jar there as well, but feel as if I'm shooting in the dark as no messages are returned and nothing is written to the logs, just get the 500 Cheers Ron -- View this message in context: http://drools-java-rules-engine.46999.n3.nabble.com/drools-server-how-to-... Sent from the Drools - User mailing list archive at Nabble.com.