Hi there.
I´m currently designing a kitchen and I have all the furniture in separated files. Each time I need a model I jus insert it as a BlockInstance in the new file. This Files have some blocks as well, things like, handles, screws, hinges, legs, etc.
I doble click in the block instance of a Drawer to edit it, but by curiosity I executed the SelBadObjects command and Rhino selected the block instances that are inside the main blockinstance (Legs).
Why did Rhino selected Block Instances?
(I wnet back to each file of a part that makes de assembly and they had no errors in any surface)