thank you for looking at my forum thread.

- All planes look normal, with exception of the 3D-plane which is empty.
- SH3D file size is 3258KB.
- Opening the SH3D file with ZIP tool gives 40 files named "0" - "39", plus one file named "Home", all without extensions.

More about our problem model:

- there are two layouts side by side (ground floor 1st floor). Before the 3D view disappeared, they were shown shown on the 3D view.

- there was something wrong: on the 3D view an object (circular stairs) was shown "in" a wall, which was not shown on 2D plane and not listed on objects list in lower left plane.