Attached is a drawing that I'm having trouble with. The gold solid is was created and the cylinder, cone and slot near the x-axis were cut out using solid subtraction.

Then I created a skin from the green curves below the red solid. using extrude surface along zAxis I created three red solids I then used Solid subtract to create a
channel between the cone and the slot the two solids that were created from the curved sides of the skin surface subtracted correctly but the main section failed in a
funny way. if you hide the red solid it looks like the subtraction removed the interior of the gold solid but left the top surface. any ideas about what I did wrong?

I didn't realize I could not attach a bbcd file so attached is a .dwg the red piece is the curved object protruding from the top of the part.