Stl filtering out solids problem

[Anonymous]

Hello,

When I'm trying to stlout my object it is being filtered out.
What problem may be?
How to fix it?
Thank you guys

[Patchy]

Using QSELECT and find out which one is Solid and which one is Surface

[Anonymous]

Yea.. Found out that it was all only surfaces... Thank you . 
I have another problem - I imported stp file into autocad, but I can't edit it (union, substract and etc..)
Do you know where is the problem?

Thanks

[Patchy]

Is it one 3d Solid?  so I don't think you can Subtract .......but you can use Slice