June 02, 2018, 02:32:05 am

Nothing like having to uninstall newer versions before an older version can be installed.
Anyway, finally there.
In AutoCAD 2017.
I am able to create boxes using the box shape (see Mortens pic of AutoCAD's interface). It's identified as a Mass Element. But also if I convert those to 3D Solid the objects (pic 2) it also works OK, and are able to be used as nodes in Lumion.
Your boxes are identified as 3D Solids, so I am not sure why the difference. Did you do some other method of creating or converting them?
Have attached your original DWG with your boxes, plus the middle 3 boxes are mine as mass elements, the other green boxes are mas elements converted to 3D Solids.
Are you able to use that file and get nodes to work?