Having a problem creating a solid object

 From:  Frenchy Pilou (PILOU)
4298.7 
Another possibilitiy for the lateral side
if you want keep the lines of the start you can take 2 segments oposited
join the other lines and make a sweep 2 rails ;)
You will obtain a tensile surface on the lateral side!

EDITED: 15 Jul 2018 by PILOU