Revit API Assembly members validation

[h.nijboerWAJKH]

Hello,

I encountered some strange behavior when adding elements to an assembly. 

In Revit when I try to add an element to an existing Assembly which has Phase 'Created', and the element which I try to add has a different Phase I get a message: 

Selected Element(s) cannot be added to the assembly. Elements must have the same phases as the assembly to be included in the assembly.

However when I am updating the same AssemblyInstance with new members using AddMemberIds method on the AssemblyInstance it works:

assemblyInstance.AddMemberIds(elementIdsToAddToAssembly);

When I am selecting the elements in the UI I see different phases for elements in the same assembly.

This shouldn't be possible I think?

Greetz,

[jeremytammik]

That sounds as if it should not be possible, indeed.

Please submit a minimal reproducible case that we can share with the development team for analysis and possible rectification:

https://thebuildingcoder.typepad.com/blog/about-the-author.html#1b

[h.nijboerWAJKH]

Here you have my Revit test file with some specific test code for the attached Revit file..

        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            var document = commandData.Application.ActiveUIDocument.Document;

            // Assembly instance with CreatedPhase: Phase 1
            var assemblyInstance = (AssemblyInstance)document.GetElement(new ElementId(296092));

            using (var transaction = new Transaction(document))
            {
                transaction.Start("Combine walls");

                // Wall with CreatedPhase: Phase 2
                assemblyInstance.AddMemberIds(new[] { new ElementId((296124)) });

                transaction.Commit();
            }
            return Result.Succeeded;
        }