title: C# WCF Client error
body: <p>I'm trying to call a WCF web service function to send data and I receive bellow exceptions</p>
  
  <pre><code>System.ServiceModel.FaultException: The server was unable to process the request due to an internal error.  For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the &lt;serviceDebug&gt; configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs.
  
  Server stack trace: 
     at System.ServiceModel.Channels.ServiceChannel.ThrowIfFaultUnderstood(Message reply, MessageFault fault, String action, MessageVersion version, FaultConverter faultConverter)
     at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc&amp; rpc)
     at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
     at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
     at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
  
  Exception rethrown at [0]: 
     at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
     at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&amp; msgData, Int32 type)
     at sgsGemma.WUI.WebServiceOnDemand.WebService.IDataSync.UpdateProductCategoryAssociations(String ProductId, String Outline, Boolean isFirstCall)
     at sgsGemma.WUI.WebServiceOnDemand.WebService.DataSyncClient.UpdateProductCategoryAssociations(String ProductId, String Outline, Boolean isFirstCall) in C:\antg\Addins\Gemma\Baseline\Sources\WinForms\sgsGemma.WUI.WebServiceOnDemand\sgsGemma.WUI.WebServiceOnDemand\Service References\WebService\Reference.cs:line 150
     at sgsGemma.WUI.WebServiceOnDemand.sgsgmWebServiceOnDemandF.SendItemCategoryAssociationsToWebService() in C:\antg\Addins\Gemma\Baseline\Sources\WinForms\sgsGemma.WUI.WebServiceOnDemand\sgsGemma.WUI.WebServiceOnDemand\sgsgmWebServiceOnDemandF.cs:line 704
  15:29:32.80 Th1 Error sgsGemma.WUI.WebServiceOnDemand.sgsgmWebServiceOnDemandF SendItemCategoryAssociationsToWebService System.ServiceModel.FaultException: The server was unable to process the request due to an internal error.  For more information about the error, either turn on IncludeExceptionDetailInFaults (either from ServiceBehaviorAttribute or from the &lt;serviceDebug&gt; configuration behavior) on the server in order to send the exception information back to the client, or turn on tracing as per the Microsoft .NET Framework SDK documentation and inspect the server trace logs.
  
  Server stack trace: 
     at System.ServiceModel.Channels.ServiceChannel.ThrowIfFaultUnderstood(Message reply, MessageFault fault, String action, MessageVersion version, FaultConverter faultConverter)
     at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc&amp; rpc)
     at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
     at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
     at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
  
  Exception rethrown at [0]: 
     at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
     at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData&amp; msgData, Int32 type)
     at sgsGemma.WUI.WebServiceOnDemand.WebService.IDataSync.UpdateProductCategoryAssociations(String ProductId, String Outline, Boolean isFirstCall)
     at sgsGemma.WUI.WebServiceOnDemand.WebService.DataSyncClient.UpdateProductCategoryAssociations(String ProductId, String Outline, Boolean isFirstCall) in C:\antg\Addins\Gemma\Baseline\Sources\WinForms\sgsGemma.WUI.WebServiceOnDemand\sgsGemma.WUI.WebServiceOnDemand\Service References\WebService\Reference.cs:line 150
     at sgsGemma.WUI.WebServiceOnDemand.sgsgmWebServiceOnDemandF.SendItemCategoryAssociationsToWebService() in C:\antg\Addins\Gemma\Baseline\Sources\WinForms\sgsGemma.WUI.WebServiceOnDemand\sgsGemma.WUI.WebServiceOnDemand\sgsgmWebServiceOnDemandF.cs:line 704
  </code></pre>
  
  <p>I called in same application and same form an other function of same web service and it works fine. But this one not. </p>
  
  <p>Can anyone please explain to me what means this exception and how can fix it? 
  Thank you</p>