WSO2 DOCTYPE not allowed calling REST Api

i m working with this proxy:

<?xml version="1.0" encoding="UTF-8"?>
<proxy xmlns="http://ws.apache.org/ns/synapse"
       name="PubMedDataProxy"
       transports="https,http"
       statistics="disable"
       trace="disable"
       startOnLoad="true">
   <target>
      <inSequence>
         <call>
            <endpoint>
               <http method="get"
                 uri-template="http://eutils.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=omim&amp;Mdb=pubmed&amp;id=230900"/>
            </endpoint>
         </call>
         <log level="custom">
            <property name="MyLOg" expression="//eLinkResult/DbFrom/text()"/>
         </log>
         <respond/>
      </inSequence>
      <outSequence>
         <send/>
      </outSequence>
   </target>
   <description/>
</proxy>

i get this exception:

TID: [0] [ESB] [2015-05-21 13:45:34,838] ERROR {org.apache.synapse.transport.passthru.util.RelayUtils} -  Error while building Passthrough stream {org.apache.synapse.transport.passthru.util.RelayUtils}
org.apache.axiom.om.OMException: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[2,142]
Message: DOCTYPE is not allowed
    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.axis2.builder.ApplicationXMLBuilder.processDocument(ApplicationXMLBuilder.java:81)
    at org.apache.synapse.transport.passthru.util.DeferredMessageBuilder.getDocument(DeferredMessageBuilder.java:118)
    at org.apache.synapse.transport.passthru.util.RelayUtils.builldMessage(RelayUtils.java:107)
    at org.apache.synapse.transport.passthru.util.RelayUtils.buildMessage(RelayUtils.java:82)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:68)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:239)
    at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.mediateFromContinuationStateStack(Axis2SynapseEnvironment.java:556)
    at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:198)
    at org.apache.synapse.core.axis2.SynapseCallbackReceiver.handleMessage(SynapseCallbackReceiver.java:488)
    at org.apache.synapse.core.axis2.SynapseCallbackReceiver.receive(SynapseCallbackReceiver.java:170)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.synapse.transport.passthru.ClientWorker.run(ClientWorker.java:225)
    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:745)
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[2,142]
Message: DOCTYPE is not allowed
...

Calling the service in a normal REST client i get the XML result withouth any problem.

The issue occured when the proxy tries to parse the resulting xml. Indeed removing the Log mediator with the property inside the proxy returns the result correctly. What am i missing?

Solution

Add the following to your proxy:

<parameter name="ApplicationXMLBuilder.allowDTD">true</parameter>