Dwg-solid : Valid brep not exported

I can’t make this object to be exported as dwg solid.
It is closed and valid.
I had to clean the section and re-extrude it. And now it is exportable.
I know the model was not really well done but why rhino give me no hint about my ‘mess’ ?

Any clue ?
export_valid_issue.3dm (947.6 KB)

Hello - It looks to me like there is a zero area surface in the base plane


If you replace each end with a single trimmed plane and then RemoveAllnakedMicroEdges (these are left over from the original and need to be dealt with), the thing works ok.


Thanks. I didn’t know about this one.
But my point was how rhino could help me find why my object (even if valid) can’t be exported.