WCF - Decorating IEnumerable<T> with DataMember causes Exception:The underlying connection was closed: The connection was closed unexpectedly

Question

I have created a WCF service which returns IEnumerable<CyberResourceProvisioningAction>.

The CyberResourceProvisioningAction type has a property of AccountInformation IEnumerable<CyberResourceProvisioningActionAccountInfo>. When I decorate the AccountInformation property with DataMemberAttribute I receive the exception:

WCF System.Net.WebException: The underlying connection was closed: The connection was closed unexpectedly

Obviously a very generic exception, but my Google-fu indicates that the issue most commonly occurs when returning large numbers of objects in a collection. The suggested fix is to set the <dataContractSerializer maxItemsInObjectGraph="2147483646"/>. Unfortunately this has not fixed my issue. (Didn't think it would as I am returning a small amount of data).

The properties are being set correctly so I am pretty sure my issue has to do with my serialization configuration. Is there something wrong with my classes which is causing the WCF service to error in this way?

[DataContract]
public class CyberResourceProvisioningAction
{
    [DataMember]
    public string Action { get; set; }

    [DataMember]
    public DateTime RcdChgDateTime { get; set; }

    [DataMember]
    public string CyberResourceName { get; set; }

    [DataMember]
    public IEnumerable<CyberResourceProvisioningActionAccountInfo> AccountInformation
    { get; set; }
}

CyberResourceProvisioningActionAccountInfo

[DataContract]
public class CyberResourceProvisioningActionAccountInfo
{
    [DataMember]
    public string Name { get; set; }

    [DataMember]
    public string Value { get; set; }
}

If additional configuration information is required let me know and I'll edit the post.

Answer 1

Because of the comment about "DataContract programming model violation" left by alexdej I started looking a bit closer at what was in my properties. I had a Linq type in the property and though it was an IEnumerable it wasn't being enumerated for serialization. Added a .ToList() and all is well.