I'm getting some strange behavior when making multiple async calls coming
from threads from the thread pool on a WinApp Client. The Event Log has the
following events:

Event Type: Warning
Event Source: ASP.NET 2.0.50727.0
Event Category: Web Event
Event ID: 1309
Date: 6/18/2006
Time: 10:44:40 AM
User: N/A
Computer: LAPTOP
Description:
Event code: 3005
Event message: An unhandled exception has occurred.
Event time: 6/18/2006 10:44:40 AM
Event time (UTC): 6/18/2006 2:44:40 PM
Event ID: cb22619132d040cbb26b655619f272e8
Event sequence: 52
Event occurrence: 1
Event detail code: 0

Application information:
Application domain: 86135903-1-127951154375312500
Trust level: Full
Application Virtual Path: /WebService
Application Path: C:\QPID\WebService\
Machine name: LAPTOP

Process information:
Process ID: 6096
Process name: WebDev.WebServer.EXE
Account name: LAPTOP\aventura

Exception information:
Exception type: HttpException
Exception message: Server cannot clear headers after HTTP headers have
been sent.

Request information:
Request URL: http://localhost:1497/WebService/AttachmentServices.asmx
Request path: /WebService/AttachmentServices.asmx
User host address: 127.0.0.1
User: LAPTOP\aventura
Is authenticated: True
Authentication Type: NTLM
Thread account name: LAPTOP\aventura

Thread information:
Thread ID: 4
Thread account name: LAPTOP\aventura
Is impersonating: False
Stack trace: at System.Web.HttpResponse.ClearHeaders()
at
System.Web.Services.Protocols.SoapServerProtocol.WriteException(Exception e,
Stream outputStream)
at System.Web.Services.Protocols.ServerProtocolFactory.Create(Type type,
HttpContext context, HttpRequest request, HttpResponse response, Boolean&
abortProcessing)
at
System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type
type, HttpContext context, HttpRequest request, HttpResponse response)

Then I get another one from WSE 3.0 in the Event Log

Event Type: Error
Event Source: Microsoft WSE 3.0
Event Category: None
Event ID: 0
Date: 6/18/2006
Time: 10:44:40 AM
User: N/A
Computer: LAPTOP
Description:
HTTP/ASMX Message Receive Failure: System.Xml.XmlException: Data at the root
level is invalid. Line 2, position 1.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.Throw(String res, String arg)
at System.Xml.XmlTextReaderImpl.ParseRootLevelWhitespace()
at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
at System.Xml.XmlTextReaderImpl.Read()
at System.Xml.XmlTextReader.Read()
at Microsoft.Web.Services3.Xml.XmlSkipDTDReader.Read()
at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean
preserveWhitespace)
at System.Xml.XmlDocument.Load(XmlReader reader)
at Microsoft.Web.Services3.SoapEnvelope.Load(Stream inStream)
at
Microsoft.Web.Services3.WseProtocol.CreateRequestSoapEnvelope(SoapServerMessage message)
at
Microsoft.Web.Services3.WseProtocol.GetRequestEnvelopeFromMessage(SoapServerMessage message)

Finally, I catch an exception via the threaded exception handler on a
winform app.

It is an InvalidOperationException that says "There was an error during
async processing." The Inner exception is another InvalidOperationException
that says ""Response is not well-formed XML." That has an inner exception of
Type XopDocumentException with a strange message stating {"WSE1608: No XOP
parts were located in the stream for the specified content-id:
<0.632862250640781250@example.org>"}

Any Ideas?

Martin,

Thanks for your response. No I'm not calling ClearHeaders explicitly.

Thanks

Andy

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