DocuSign Connect响应每次都为空

我正在尝试设置一个连接侦听器。我目前正在使用我在Azure上托管的C#WCF服务。我可以点击我的服务方法，但每次来自docusign的响应都是空的。在日志中，信封状态xml有值，但它只是没有被正确发送或反序列化。我不确定我做错了什么，而且似乎没有任何SOAP实现的可靠例子。有人能帮忙吗？可以在此处查看WSDLhttp://docusignconnectservice.azurewebsites.net/Service.svc?wsdl

服务含义

public string DocuSignConnectUpdate(DocuSignAPI.DocuSignEnvelopeInformation     envelopeInformation)
    {
        string envelopeId = "";
            if (envelopeInformation == null) return "Envelope is null";
            else return envelopeInformation.EnvelopeStatus.EnvelopeID;
    }

服务合同

[ServiceContract(Namespace = "http://www.docusign.net/API/3.0")]
public interface IService
{
    [OperationContract]
    [XmlSerializerFormatAttribute]
    string DocuSignConnectUpdate(DocuSignAPI.DocuSignEnvelopeInformation envelopeInformation);
    [OperationContract]
    string HelloWorld(string inputString);

DocuSign日志条目

10/6/2014 1:30:12 AM Envelope Data:<?xml version="1.0" encoding="utf-8"?><DocuSignEnvelopeInformation xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.docusign.net/API/3.0"><EnvelopeStatus><RecipientStatuses><RecipientStatus><Type>Signer</Type><Email>email</Email><UserName>Username</UserName><RoutingOrder>1</RoutingOrder><Sent>2014-10-05T17:49:36.58</Sent><DeclineReason xsi:nil="true" /><Status>Sent</Status><RecipientIPAddress /><CustomFields /><AccountStatus>Active</AccountStatus><RecipientId>2a10b0ab-63f1-4df9-9258-36b97b5db120</RecipientId></RecipientStatus></RecipientStatuses><TimeGenerated>2014-10-05T18:30:09.644588</TimeGenerated><EnvelopeID>6d7692e6-3f5c-4889-914f-942b2bd83447</EnvelopeID><Subject> Signature Request on Document</Subject><UserName>Username</UserName><Email>email</Email><Status>Sent</Status><Created>2014-10-05T17:49:35.503</Created> <Sent>2014-10-05T17:49:36.613</Sent><ACStatus>Original</ACStatus><ACStatusDate>2014-10-05T17:49:35.503</ACStatusDate><ACHolder></ACHolder><ACHolderEmail></ACHolderEmail><ACHolderLocation>DocuSign</ACHolderLocation><SigningLocation>Online</SigningLocation><SenderIPAddress>ip </SenderIPAddress><EnvelopePDFHash /><CustomFields /><AutoNavigation>true</AutoNavigation><EnvelopeIdStamping>true</EnvelopeIdStamping><AuthoritativeCopy>false</AuthoritativeCopy><DocumentStatuses><DocumentStatus><ID>1</ID><Name>F_1040.pdf</Name><TemplateName /><Sequence>1</Sequence></DocumentStatus></DocumentStatuses></EnvelopeStatus></DocuSignEnvelopeInformation> 10/6/2014 1:30:12 AM Response: <s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/"><s:Body xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><DocuSignConnectUpdateResponse xmlns="http://www.docusign.net/API/3.0"><DocuSignConnectUpdateResult>Envelope is null</DocuSignConnectUpdateResult></DocuSignConnectUpdateResponse></s:Body> </s:Envelope>