Hi,

I am working on an ASP.NET web app using Visual Studio 2008 and a third-party library.

Things are fine in my development environment. Things are also good if the web app is deployed in Debug configuration. However, when it is deployed in Release mode, SerializationExceptions appear intermittently, breaking other functionality.

In the Windows event log, the following error can be seen:

"An unhandled exception occurred and the process was terminated.

Application ID: DefaultDomain

Process ID: 3972

Exception: System.Runtime.Serialization.SerializationException

Message: Unable to find assembly 'MyThirdPartyLibrary, Version=1.234.5.67, Culture=neutral, PublicKeyToken=3d67ed1f87d44c89'.

StackTrace: at System.Runtime.Serialization.Formatters.Binary.BinaryAssemblyInfo.GetAssembly( ) at System.Runtime.Serialization.Formatters.Binary.ObjectReader.GetType(BinaryAsse mblyInfo assemblyInfo, String name) at System.Runtime.Serialization.Formatters.Binary.ObjectMap..ctor(String objectName, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA, Object[] typeInformationA, Int32[] memberAssemIds, ObjectReader objectReader, Int32 objectId, BinaryAssemblyInfo assemblyInfo, SizedArray assemIdToAssemblyTable) at System.Runtime.Serialization.Formatters.Binary.ObjectMap.Create(String name, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA, Object[] typeInformationA, Int32[] memberAssemIds, ObjectReader objectReader, Int32 objectId, BinaryAssemblyInfo assemblyInfo, SizedArray assemIdToAssemblyTable) at System.Runtime.Serialization.Formatters.Binary._BinaryParser.ReadObjectWithMa pTyped(BinaryObjectWithMapTyped record) at System.Runtime.Serialization.Formatters.Binary._BinaryParser.ReadObjectWithMa pTyped(BinaryHeaderEnum binaryHeaderEnum) at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run() at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(Header Handler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Str eam serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Remoting.Channels.CrossAppDomainSerializer.DeserializeObject(Me moryStream stm) at System.AppDomain.Deserialize(Byte[] blob) at System.AppDomain.UnmarshalObject(Byte[] blob)

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp."

Using FUSLOGVW.exe (i.e., Assembly Binding Log Viewer), I can see the problem is that IIS attempts to find MyThirdPartyLibrary in directory C:\windows\system32\inetsrv. It refuses to look in the bin folder of the web app, where the DLL is actually located.

Does anyone know what the problem is?

Thanks,

Calvin