Non manifold edge when attempting to solid union

the text dot is showing an overhang condition


It reads: Intersection curve ends at a non-manifold edge

Is this a limitation of the geometry?
form-internalized.gh (202.8 KB)
Thanks

Yes this sis not possible just like that.

It looks like the boxes are only touching along an edge or corner. The coincident edge is the reason for the non-manifold error you see…

What’s your goal with the geometry?

If you want to print this, offset everything by a tiny bit and try to run the solid union. Or forget about the solid union and export disjoint meshes.

It’s used as a Revit mass, so it is ideally a solid joined brep.

As written above, I would either offset all solids a tiny bit or move the faces adjacent to the non manifold edges a tiny bit which would then create a tiny gap.