WCF - An error occurred while receiving the HTTP response to http://xxxxx/Service/

Question

I am making this call in my WCF service:

public User GetStudentRecord(string userName)
    {
        try
        {
            return new DashboardFacade().GetStudentRecord(userName);
        }
        catch (Exception ex)
        {
            ServiceFault fault = new ServiceFault();
            fault.Operation = "GetStudentRecord";
            fault.Reason = "Who knows...";
            fault.Message = ex.Message;
            throw new FaultException<ServiceFault>(fault, fault.Message, new FaultCode(fault.Reason), fault.Operation);
        }
    }

DashboardFacade().GetStudentRecord(..) is defined like this:

public User GetStudentRecord(string userName)
{
    User user = ctx.Users.Where(x => x.ADUserName == userName).SingleOrDefault();
    return user;
}

ctx is my DbContext. I am using Entity Framework Code First. The User object looks like this:

public class User
{
    public User()
    {
        //UserDetails = new UserDetail();
    }
    [Key]
    public Guid MasterKey { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string ADUserName { get; set; }
    public string UserType { get; set; }
    public virtual UserDetail UserDetails { get; set; }
    public Nullable<DateTime> LastModifiedDate { get; set; }
}

And finally, you probably need to see the web.config on the WCF Application:

<?xml version="1.0"?>
    <configuration>
      <connectionStrings>
        <add name="NotMyDBContextDB" connectionString="[omitted]" providerName="System.Data.SqlClient"/>
        <add name="ApplicationContext" connectionString="Data Source=.;Initial Catalog=MyApp;Integrated Security=True;Pooling=False" providerName="System.Data.SqlClient"/>
      </connectionStrings>
   <system.web>
     <compilation debug="true" targetFramework="4.0"/>
   </system.web>
   <system.serviceModel>
     <behaviors>
       <serviceBehaviors>
          <behavior>
             <serviceMetadata httpGetEnabled="true"/>
             <serviceDebug includeExceptionDetailInFaults="true"/>
          </behavior>
        </serviceBehaviors>
      </behaviors>
      <serviceHostingEnvironment multipleSiteBindingsEnabled="true"/>
  </system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
<directoryBrowse enabled="true"/>
</system.webServer>
</configuration>

Can anyone point me to where I am going wrong here?

This is the exact error I am getting:

An error occurred while receiving the HTTP response to http://localhost:5843/MyService.svc. This could be due to the service endpoint binding not using the HTTP protocol. This could also be due to an HTTP request context being aborted by the server (possibly due to the service shutting down). See server logs for more details.

Inner Exception:
The underlying connection was closed: An unexpected error occurred on a receive.

Inner Exception:
Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

Inner Exception:
An existing connection was forcibly closed by the remote host

Answer 1

Found the root cause after a lot of swearing and thinking of how nice the weather is outside. I remove the virtual keyword from the UserDetails object that is inside the User object.

Now it works!

As far as why this caused an issue, my assumptions are serialization or DbContext issues, but I will have to look more into it, not sure.

I'm going outside now.

So for reference, if you wound up here and have no idea what is going on, among all the other things you should look at (size, timeout, etc):

Check to see if your object has virtual keyword on it.

Answer 2

I had this problem and in my case, the issue was the WCF service was returning a class that had a property with only a getter and no setter. I was trying to prevent the property from being modified by the receiver. To get around this, see this...

WCF Services and Object Constructors

Answer 3

I had the same error.

In my case I have a table with an int column called OEM. In the model layer I have a class (DTO) with that column represented by an Enum. There was a row in the table which value in OEM colum was not valid. When I was trying to bring all data using LINQ, there was an error that wasn't captured by VisualStudio. That error raised when WCF tried to retrieve the message.

Answer 4

I had the same Exception but none of the answers above gave me a solution. I figured out the error by defining a trace in web.config :

<system.diagnostics>
<sources>
  <source propagateActivity="true" name="System.ServiceModel" switchValue="Information, ActivityTracing">
    <listeners>
      <add type="System.Diagnostics.DefaultTraceListener" name="Default">
        <filter type="" />
      </add>
      <add initializeData="C:/temp/tracelog.svclog" type="System.Diagnostics.XmlWriterTraceListener" name="traceListener">
        <filter type="" />
      </add>
    </listeners>
  </source>
</sources>
</system.diagnostics>

I ran the website locally, fired a few failing calls and the opened the tracelog selecting the failed entry, inside that entry I saw this exception :

The entity or complex type 'Person' cannot be constructed in a LINQ to Entities query.

Constructing the person outside of the query fixed the issue so instead of :

 var persons = (from p in db.Persons
                  select new Person
                  {
                      Id = p.Id,
                      Name = p.Name,
                      LastName = p.LastName,
                      Email = p.Email
                  }
              ).AsEnumerable();

  return persons;

I had to do :

var persons = (from p in db.Persons
                  select new 
                  {
                      Id = p.Id,
                      Name = p.Name,
                      LastName = p.LastName,
                      Email = p.Email
                  }
              ).AsEnumerable()
                //construct the complex type outside of DB  (to prevent the exception that model cannot be constructed in linq to entities)
                .Select(item =>

                    new Person
                    {
                        Id = item.Id,
                        Name = item.Name,
                        LastName = item.LastName,
                        Email = item.Email
                    }).ToList(); 

            return persons;

I could have saved alot of time if the exception message was more comprehensive, judging by all the different causes outlined in this topic I guess people will agree with me.

Anyway, this is how I figured out the issue, hopefully this will help someone else to