NHibernate collection loading, "illegal access to loading collection"

Question

I have a problem loading a collection. Setup I have is simple one-to-many association, mapped using FluentNHibernate. Entity is loaded withough exception being thrown, but accessing related collection displays "illegal access to loading collection". I'll paste relevant part of code here.

[Serializable]
[DataContract(IsReference = true)]
public partial class Department : Entity
{
    ...
    [DataMember]
    public virtual IList PressJobRun
    {
        get { return pressJobRunField; }
        protected set { pressJobRunField = value; }
    }
    ...
}

mapped as follows

public DepartmentMap()
{
    Id(x => x.Id);
    Map(x => x.Name)
        .Not.Nullable()
        .Length(100);
    HasMany(x => x.PressJobRun)
        .AsBag()
        .Inverse()
        .Cascade.AllDeleteOrphan()
        .LazyLoad()
        .BatchSize(50);
    ...
}

I've also tried to disable lazy loading, by excluding the line and by calling .Not.LazyLoad(), however end is the same.

    using (var tx = m_Repository.Session.BeginTransaction())
    {
        var depts = m_Repository.Session.CreateCriteria().List();
        var dept = depts[0];
        ...
    }

I realize exposing Session is not the thing to do, but this was in attempts to make sure that session is open.

When I drill down the exception I see following stack trace:

   at NHibernate.Collection.AbstractPersistentCollection.Initialize(Boolean writing)
   at NHibernate.Collection.AbstractPersistentCollection.Read()
   at NHibernate.Collection.AbstractPersistentCollection.ReadSize()
   at NHibernate.Collection.PersistentBag.get_Count()
   at NHibernate.DebugHelpers.CollectionProxy`1.get_Items()

The interesting gremlin comes here. I've set breakpoint on setter line of PressJobRun property.

if I step over it and quick watch pressJobRunField, I see the "illegal access to loading exception".
if I first quick watch value variable, I see the loaded collection. Stepping over setter line works as expected.

What I use

Visual Studio 2012, targeting .NET 4
NHibernate 3.3.1.400
SQL CE 4
Castle
Castle AutoTx facitlity
I manage session per WCF request myself

What I've tried

disabling lazy loading
made sure that session is open, and that it's same session during execution of offending code
toggled Inverted map of collection (thought I believe it should be inverted)
cleaned and rebuilt solution
made sure in Configuration Manager that all projects in solution are being built
set debugger to break on all thrown exceptions. Debugger doesn't break with exception that i see set in collection

NHibernate collection loading, "illegal access to loading collection"

1 Answers