When trying to begin a second transaction on a IFCStore, a NullReferenceException is thrown. My goal is to separate the classic IFC initialization (credentials, project, building) from the real “design” (adding beams, …).
To achieve this, I need to create separate transactions on the IFCStore I’m using.

1. I create a transaction to add the project and building informations and commit
2. I create a second transaction to add various elements. When creating this transaction, it fails. No details are given and I can’t debug it further than my code.
   Here is a sample code :

public myIFCClass()
{
    var credentials = CreateCredentials();

    LocalIFCModel = IfcStore.Create(credentials, XbimSchemaVersion.Ifc4, XbimStoreType.InMemoryModel);
    using (LocalIFCModel)
    {
        using (var txn = LocalIFCModel.BeginTransaction("Creating IFC"))
        {
            LocalIFCProject = InitializeProject(LocalIFCModel, "PROJECT : TEST");
            LocalIFCBuilding = CreateBuilding(LocalIFCModel, LocalIFCProject, "BUILDING : TEST");
            txn.Commit();
        }
    }


    using (LocalIFCModel)
    {
        using (var txn = LocalIFCModel.BeginTransaction("Do something else")) // HERE !
        {
            // Do something else
            txn.Commit();
        }
    }
}

Expected : beginning a second transaction shouldn’t cause any problems I guess.

I tried :

• Changing the transaction description
• Changing the transaction variable name
• Disposing the first transaction after its commit
• Using a model that’s not a class member