<IIS_Log_filename>:<number>:<date_time> W3SVC1 <ip-address> POST /ews/Exchange.asmx SoapAction=xxxxxxxxxx xxx x xxxx 500 0 0
This problem always occurs when you troubleshoot an Exchange Web Services (EWS) application. In this situation, the EWS application might also throw an exception with the following call stack information:
Encountered unhandled exception: System.Web.Services.Protocols.SoapException: Server was unable to process request. System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.Exchange.Services.ServiceExtensionManager.TraceMessage(Stream stream, Trace tracer)
at Microsoft.Exchange.Services.ResponseLogger.AfterSerializeResponse(SoapMessage message)
at Microsoft.Exchange.Services.ServiceExtensionManager.DoAfterSerializeResponse(SoapMessage message)
at Microsoft.Exchange.Services.ServiceExtensionManager.<>c__DisplayClass1.<ProcessMessage>b__0()
at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(TryDelegate tryDelegate, FilterDelegate filterDelegate, CatchDelegate catchDelegate)
at Microsoft.Exchange.Diagnostics.ExWatson.SendReportOnUnhandledException(MethodDelegate methodDelegate, IsExceptionInteresting exceptionInteresting, Boolean terminating)
at Microsoft.Exchange.Services.Core.ServiceDiagnostics.TraceErrorOnUnhandledException(MethodDelegate methodDelegate)
at System.Web.Services.Protocols.SoapMessage.RunExtensions(SoapExtension[] extensions, Boolean throwOnException)
at Microsoft.Exchange.Services.ServiceExtensionManager.TraceMessage(Stream stream, Trace tracer)
at Microsoft.Exchange.Services.ResponseLogger.AfterSerializeResponse(SoapMessage message)
at Microsoft.Exchange.Services.ServiceExtensionManager.DoAfterSerializeResponse(SoapMessage message)
at Microsoft.Exchange.Services.ServiceExtensionManager.<>c__DisplayClass1.<ProcessMessage>b__0()
at Microsoft.Exchange.Common.IL.ILUtil.DoTryFilterCatch(TryDelegate tryDelegate, FilterDelegate filterDelegate, CatchDelegate catchDelegate)
at Microsoft.Exchange.Diagnostics.ExWatson.SendReportOnUnhandledException(MethodDelegate methodDelegate, IsExceptionInteresting exceptionInteresting, Boolean terminating)
at Microsoft.Exchange.Services.Core.ServiceDiagnostics.TraceErrorOnUnhandledException(MethodDelegate methodDelegate)
at System.Web.Services.Protocols.SoapMessage.RunExtensions(SoapExtension[] extensions, Boolean throwOnException)