Hello,
The following 3d model when exported the curve will not be exported with the object
Attached you can find the 3dm model, if you export to DWG it will be empty.
prova.dwg (31.8 KB)
here is the output
here is the input
gaga.3dm (127.5 KB)
If you could resolve the problem, It’s critical that it notifies you if any curve is missing.
Also why would that curve be missing
Your object is a block instance. It contains one bad (invalid) object - the curve that does not export. Unfortunately SelBadObjects does not select the block instance even though it contains the bad curve. Invalid curves do not get exported by Rhino. The fix is to explode the block, explode the curve and rejoin. The curve will then be vaild and it will export correctly.
This problem still exists in V8 and V9. Nothing is going to be fixed for Rhino 7, and probably not for V8. Maybe V9 will address it.
I created a bug report for this: