MAC Powerbook G4, OS 10.5.8
Shark V5

I did the following:
1 Create 2D of trapazoidal sheet with constraints
2 Go to 3D, select the Lines of the perimeter of the sheet
3 Extrude to random thickness and change to proper thickness of .063 in control panel
4 Make Instance copy off extruded sheet, call it Top1 and put it in a new layer named Top

So far, everything is fine. I change a controlling dimension and it flows through everything.:)

5 Save the file using Save As and put it in a new job folder
6 Quit Shark
7 Re-open shark after several hours ans session with Cobalt, quitting Cobalt before opening.

8 The only things in the file are the 2D constrained lines. Everything else is gone although the layers are there.:eek:

What did I do wrong.:confused:

Thanks Richard,
It seems to work if I select 3D before opening my drawing.