问WSO2 ESB 4.8.1中的XSLT转换错误

EN

Unable to perform XSLT transformation using : Value {name ='null', keyValue ='gov:/xslt/Interface.xslt'} against source XPath : s11:Body/child::*[position()=1] | s12:Body/child::*[position()=1] reason : Unable to create an OMElement using XSLT result  {org.apache.synapse.mediators.transform.XSLTMediator}
org.apache.synapse.SynapseException: Unable to create an OMElement using XSLT result 
    at org.apache.synapse.mediators.transform.XSLTMediator.performXSLT(XSLTMediator.java:302)
    at org.apache.synapse.mediators.transform.XSLTMediator.mediate(XSLTMediator.java:191)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:77)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:47)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:131)
    at org.apache.synapse.core.axis2.ProxyServiceMessageReceiver.receive(ProxyServiceMessageReceiver.java:166)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.synapse.transport.passthru.ServerWorker.processEntityEnclosingRequest(ServerWorker.java:411)
    at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:183)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: org.apache.axiom.om.OMException: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[4,16]
Message: Content is not allowed in prolog.
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:296)
    at org.apache.axiom.om.impl.llom.OMDocumentImpl.getOMDocumentElement(OMDocumentImpl.java:109)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.getDocumentElement(StAXOMBuilder.java:570)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.getDocumentElement(StAXOMBuilder.java:566)
    at org.apache.synapse.util.jaxp.StreamResultBuilder.getNode(StreamResultBuilder.java:87)
    at org.apache.synapse.mediators.transform.XSLTMediator.performXSLT(XSLTMediator.java:300)
    ... 12 more
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[4,16]
Message: Content is not allowed in prolog.
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:598)
    at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225)
    at org.apache.axiom.util.stax.dialect.SJSXPStreamReaderWrapper.next(SJSXPStreamReaderWrapper.java:138)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:681)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214)
    ... 17 more

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:con="http://com.example/cdm/contract/v1" xmlns:lic="http://com.example/cdm/license/v1" xmlns:org="http://com.example/cdm/organization/v1" xmlns:tns="http://com.example/cdm/order/v1" xmlns:tns1="http://com.example/cdm/customer/v1" xmlns:tns3="http://com.example/cdm/address/v1" xmlns:tns4="http://com.example/cdm/person/v1" xmlns:tns5="http://com.example/cdm/productoffer/v1" xmlns:tns6="http://com.example/cdm/product/v1" xmlns:tns7="http://com.example/cdm/productofferprice/v1" exclude-result-prefixes="tns tns1 tns4 tns3 tns5 tns6 tns7" version="1.0">
  <xsl:template match="/tns:OrderRequest">
    <tns:OrderRequest>
      <tns:Order>
        <tns:OrderHeader>
          <tns:OrderNumber>
            <xsl:value-of select="tns:OrderHeader/tns:OrderNumber" />
          </tns:OrderNumber>
            </tns:OrderHeader>
         </tns:Order>
    </tns:OrderRequest>
  </xsl:template>
</xsl:stylesheet>