@tig said:

Your model needs a major tidy up.
If you combine the [exploded] parts into one group it's just not a 'Solid'.
There are overlapping edge, flaps, tiny holes etc.
Use thomthom's solid-inspector to see these issues, and some careful adjustments to fix them.

Because tools like this and my newer 'Slicer5' work by intersecting planes with the group and deducing faces from the intersecting edges produced, non-solids will often produce unexpected results - e.g. if a slice's edges are missing and can't form a face to then extrude into the slice, or perhaps deciding what is a filled face and what is a void becomes untenable...

I cannot see the +flattened copies on my drawing..why?? i have windows 7 64b and skup 8..what is wrong with this plug in?? I have the same problem with the other slice plug ins. Im trying with very basic forms and NOTHING.