Creating surfaces between 2 polylines

[EliabuRada]

Hey,
I am having trouble to create a srf between this é polyline and i just cant understand why,
does anybody knows?

offset.gh (13.6 KB)
polyline.3dm (1.6 MB)

[HS_Kim]

Like this?

offset_re.gh (16.6 KB)

[EliabuRada]

Wonderful, thanks