Shelling not work

(Rhino 6)
Shell the upper face, thickness one unit. Not Work.
shelling not work good.3dm (84.3 KB)

Hello davide76,

I was able to get the shell command to work but got a warning: " Shell Result is not solid". Edge Analysis showed 6 naked edges. shelling not work good_al.3dm (154.7 KB)

The flat surface was extruded with the gumball, a simple example, but the shell command on the discontinuity produces a bad result.
The oddities of Rhino!