Error report

Error on http://validator.w3.org/unicorn/check?ucn_uri=referer&ucn_task=conformance:

class org.apache.xmlbeans.XmlException
error: Unexpected end of file after null
org.apache.xmlbeans.impl.store.Locale$SaxLoader.load(Locale.java:3486)
org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1276)
org.apache.xmlbeans.impl.store.Locale.parseToXmlObject(Locale.java:1263)
org.apache.xmlbeans.impl.schema.SchemaTypeLoaderBase.parse(SchemaTypeLoaderBase.java:345)
org.w3.x2009.x10.unicorn.observationresponse.ObservationresponseDocument$Factory.parse(Unknown Source)
org.w3c.unicorn.response.impl.DefaultResponseXBeans.<init>(DefaultResponseXBeans.java:60)
sun.reflect.GeneratedConstructorAccessor23.newInstance(Unknown Source)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
org.w3c.unicorn.response.ResponseFactory.getResponse(ResponseFactory.java:24)
org.w3c.unicorn.request.URIRequest.doRequest(URIRequest.java:141)
org.w3c.unicorn.RequestThread.run(RequestThread.java:66)