Hello all.
Rudy here.

Not sure why, but my internal shape will not extrude (with caps).

I had my initial shape, offset it a bit smaller (negative value) to arrive at my internal contour.

I want to make a solid in between the contours, but as the extrernal shape will extrude, the internal one will not, (no caps), so the boolean difference eventually will fail.

Any idea why?

Thanks,
Rudy