Unexpected Assembly Derive Solution

[bcrowell]

I created a component  in a test assembly (in my quest for the holy grail of accurate interior volumes) and then derived it a part from it and the resulting solid is missing a great deal of geometry.  What is missing also happens to be the part I would have wanted to keep (but it should ALL be there, minus the subtracted parts, of course).

I don't see any options about direction, etc that would affect the resulting solid the way it is coming out.  If you can help I would appreciate it.

[Daniela_Koloszko]

I am checking the problem and will let you now what is causing this.