Shelling failed

I hope that in V6 shell in examples of this kind are resolved.
(I tried with FormZ and manages to execute them).
shelling failed.3dm (153.3 KB)

No reply?

What face do you want open?
What thickness?
My first try worked, I used 2mm as the wall thickness:

If you open the file, the faces are bordered with red.
the one curve of the first object, and the two upper faces of the other object.

Added to the pile, thanks.