simple new IFC with extruded rectangle

[kbworkza]

Greetings,
Is there s forum I could post this to?
I just want to include am extruded rectangle in the IFC file (in the Project).
This fails at SHAPEREPRESENTATION - exception value cannot be null
it probably needs a few more objects to complete the inclusion of the extrusion in the Project.

` ifc.Repository.CurrentModel = new ifc.Model(Name: "hello_project_output");
ifc.Project project = new ifc.Project();
project.Name = new ifc.Label("my first ifc-project");
project.EndOfLineComment = new ifc.Label("creating the project");

        ifc.Building building = new ifc.Building(GlobalId: null, Name: new ifc.Label("my first ifc-model"));

        new ifc.RelAggregates(RelatingObject: project, RelatedObjects: new ifc.Set1toUnbounded_ObjectDefinition(building));

        var MRect = new ifc.RectangleProfileDef() {
            ProfileType = ifc.ProfileTypeEnum.AREA,
            XDim = 5.0,
            YDim = 5.0
        };

        var MREx = new ifc.ExtrudedAreaSolid() {
            SweptArea = MRect,
            ExtrudedDirection = new ifc.Direction(0, 0, 1),
            Depth = 5.0
        };

        var SRep = new ifc.ShapeRepresentation() { 
            ContextOfItems = project.RepresentationContexts.FirstOrDefault(),
            RepresentationType = "SweptSold",
            RepresentationIdentifier = "Body",
            Items = new ifc.Set1toUnbounded_RepresentationItem(MREx)
        };

        ifc.Repository.CurrentModel.ToStepFile();

`

[bsbock]

An example for an extruded rectangle you can find here:
https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/annex_e/basic-geometric-shape/extruded-solid.html