title: Unable to serialize the session state using stateserver
body: <p>I m getting following error and wondering if we can make System.Data.Linq.EntitySet serializable</p>
  
  <blockquote>
    <p>Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.</p>
    
    <p>Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. </p>
    
    <p>Exception Details: System.Web.HttpException: Unable to serialize the session state. In 'StateServer' and 'SQLServer' mode, ASP.NET will serialize the session state objects, and as a result non-serializable objects or MarshalByRef objects are not permitted. The same restriction applies if similar serialization is done by the custom session state store in 'Custom' mode.</p>
    
    <p>Source Error: </p>
    
    <p>An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.</p>
    
    <p>Stack Trace: </p>
    
    <p>[SerializationException: Type 'System.Data.Linq.EntitySet`1[[NES.HiLo.Data.DAO.UserResource, NES.HiLo.Data, Version=1.0.5012.39381, Culture=neutral, PublicKeyToken=null]]' in Assembly 'System.Data.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not marked as serializable.]
       System.Runtime.Serialization.FormatterServices.InternalGetSerializableMembers(RuntimeType type) +7738715
       System.Runtime.Serialization.FormatterServices.GetSerializableMembers(Type type, StreamingContext context) +258
       System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitMemberInfo() +111
       System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.InitSerialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +422
       System.Runtime.Serialization.Formatters.Binary.WriteObjectInfo.Serialize(Object obj, ISurrogateSelector surrogateSelector, StreamingContext context, SerObjectInfoInit serObjectInfoInit, IFormatterConverter converter, ObjectWriter objectWriter) +51
       System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Write(WriteObjectInfo objectInfo, NameInfo memberNameInfo, NameInfo typeNameInfo) +7636088
       System.Runtime.Serialization.Formatters.Binary.ObjectWriter.Serialize(Object graph, Header[] inHeaders, __BinaryWriter serWriter, Boolean fCheck) +461
       System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(Stream serializationStream, Object graph, Header[] headers, Boolean fCheck) +134
       System.Web.Util.AltSerialization.WriteValueToStream(Object value, BinaryWriter writer) +1577</p>
  </blockquote>