Получено исключение SOAP FAULT с ошибкой на стороне сервера. Каковы все возможные ошибки?

Question

Ниже приведена ошибка мыла, полученная при запросе счета-фактуры ARIBA.

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Body>
        <soap:Fault>
            <faultcode>soap:Server</faultcode>
            <faultstring>Fault occurred while processing.</faultstring>
        </soap:Fault>
    </soap:Body>
</soap:Envelope>

Ошибка SOAP из-за исключения ниже

ariba.channel.ws.WebServiceClient.sendSynchronousMessage(WebServiceClient.java:493)
    at ariba.channel.ws.WebServiceClient.sendSynchronousMessage(WebServiceClient.java:294)
    at ariba.channel.ws.WebServiceRequestMessageHandler.processExportRequest(WebServiceRequestMessageHandler.java:567)
    at ariba.channel.ws.WebServiceRequestMessageHandler.processRequest(WebServiceRequestMessageHandler.java:340)
    at ariba.integration.channel.RequestMessageHandler.processRequest(RequestMessageHandler.java:364)
    at ariba.channel.ws.WSChannel$RequestWorkProcessor.run(WSChannel.java:602)
Caused by: org.codehaus.xfire.fault.XFireFault: Could not receive fault.. Nested exception is java.lang.NullPointerException: null
    at org.codehaus.xfire.fault.XFireFault.createFault(XFireFault.java:89)
    at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:83)
    at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:106)
    at org.codehaus.xfire.client.Client.invoke(Client.java:354)
    at ariba.channel.ws.WebServiceClient.sendSynchronousMessage(WebServiceClient.java:439)
    ... 5 more
Caused by: org.codehaus.xfire.XFireRuntimeException: Could not receive fault.. Nested exception is java.lang.NullPointerException: null
    at org.codehaus.xfire.client.Client.onReceive(Client.java:431)
    at org.codehaus.xfire.transport.http.HttpChannel.sendViaClient(HttpChannel.java:139)
    at org.codehaus.xfire.transport.http.HttpChannel.send(HttpChannel.java:48)
    at org.codehaus.xfire.handler.OutMessageSender.invoke(OutMessageSender.java:26)
    at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131)
    at org.codehaus.xfire.client.Invocation.invoke(Invocation.java:79)
    ... 8 more
Caused by: java.lang.NullPointerException
    at ariba.channel.ws.WebServiceFaultHandler.invoke(WebServiceFaultHandler.java:100)
    at org.codehaus.xfire.handler.HandlerPipeline.invoke(HandlerPipeline.java:131)
    at org.codehaus.xfire.client.Client.onReceive(Client.java:424)
    ... 13 more