Arquivo Discussoes de Programacao e Tecnologia 
Quando eu tive esse problema, era por causa de erro na comunicação com o servidor.
Nome de domínio errado por exemplo.
Mas pode ser muitas outras coisas.
Sugiro conferir seu WSDL e ver se a aplicação tem acesso a ele e ao port que ele está tentando acessar.
Boa tarde!
Temos um web service client que funciona em homologação, mas em produção tomamos um SOAPFaultException na cabeça.
Alguém conhece a Exception abaixo?
javax.xml.ws.soap.SOAPFaultException: Could not write to XMLStreamWriter.
at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:146)
at $Proxy34.editUser(Unknown Source)
at br.com.serasa.gatewayca.ws.GatewayWS.pkcs10RequestToX509Certificate(GatewayWS.java:72)
at br.com.serasa.gatewayca.ws.GatewayWS.pkcs10Request(GatewayWS.java:95)
at br.com.serasa.gatewayca.command.BaseCommandImpl.connectToEjbcaViaWebserviceToIssue(BaseCommandImpl.java:149)
at br.com.serasa.gatewayca.command.emissao.EmissaoCommandV2.executar(EmissaoCommandV2.java:64)
at br.com.serasa.gatewayca.GCAServlet.doXml(GCAServlet.java:188)
at br.com.serasa.gatewayca.GCAServlet.doPost(GCAServlet.java:122)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:767)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:860)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:592)
at org.apache.catalina.security.SecurityUtil$1.run(SecurityUtil.java:249)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAsPrivileged(Subject.java:517)
at org.apache.catalina.security.SecurityUtil.execute(SecurityUtil.java:282)
at org.apache.catalina.security.SecurityUtil.doAsPrivilege(SecurityUtil.java:165)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:257)
at org.apache.catalina.core.ApplicationFilterChain.access$000(ApplicationFilterChain.java:55)
at org.apache.catalina.core.ApplicationFilterChain$1.run(ApplicationFilterChain.java:161)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:263)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)
at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:226)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:551)
at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:933)
at com.sun.enterprise.web.connector.httpservice.HttpServiceProcessor.process(HttpServiceProcessor.java:234)
at com.sun.enterprise.web.HttpServiceWebContainer.service(HttpServiceWebContainer.java:2164)
Caused by: javax.xml.stream.XMLStreamException
at com.sun.xml.stream.writers.XMLStreamWriterImpl.close(XMLStreamWriterImpl.java:384)
at org.apache.cxf.interceptor.StaxOutInterceptor$StaxOutEndingInterceptor.handleMessage(StaxOutInterceptor.java:166)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:247)