Exchange 2013 - The XML document ended unexpectedly

ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013);
service.Url = new Uri(exchangeUrl);
service.Credentials = new NetworkCredential(cred.Username, cred.Password);

FolderId parentFolderId = new FolderId(WellKnownFolderName.Calendar, mailbox);
var item = UserConfiguration.Bind(service, name, parentFolderId,
                                               UserConfigurationProperties.BinaryData);
item.BinaryData = value;
item.Update();

Everytime when I'm calling the Exchange Web Services for Exchange 2013 I'm getting the following message...

Microsoft.Exchange.WebServices.Data.ServiceXmlDeserializationException: The XML document ended unexpectedly.

   at Microsoft.Exchange.WebServices.Data.EwsXmlReader.Read()

   at Microsoft.Exchange.WebServices.Data.SoapFaultDetails.ParseDetailNode(EwsXmlReader reader)

   at Microsoft.Exchange.WebServices.Data.SoapFaultDetails.Parse(EwsXmlReader reader, XmlNamespace soapNamespace)

   at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ReadSoapFault(EwsServiceXmlReader reader)

   at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ProcessWebException(WebException webException)

   at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.GetEwsHttpWebResponse(IEwsHttpWebRequest request)

   at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ValidateAndEmitRequest(IEwsHttpWebRequest& request)

   at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.Execute()

   at Microsoft.Exchange.WebServices.Data.ExchangeService.GetUserConfiguration(String name, FolderId parentFolderId, UserConfigurationProperties properties)

   at Microsoft.Exchange.WebServices.Data.UserConfiguration.Bind(ExchangeService service, String name, FolderId parentFolderId, UserConfigurationProperties properties)

I the dev environment everything is working fine, but not in integration. Any ideas? Please help.

Thanks,

Bernhard