Thicken/Offset issue with surface

Hi guys,

I have some issues regarding the thicken and offset features on a surface.

I want to create a good quality surface on a profile (see picture), however when I want to thicken it, it gives me an error. Now I know the problem, but I don't know how to fix it.

Can someone give me some tips/advice to resolve this.

Thanks in advance!

Yuriy

SolidworksSurfacing