Problem with a surface extension

[peter_humphreyMC8KJ]

Hi folks

Can someone help with a problem that i have extending this surface? It is from an offset of the inner surface of the 'Shell' body.

Adjacent surfaces have worked fine, the perpendicular and tangent extension works, but the natural extension is refusing me.

It gives me this message:

THANKS

Peter

[Phil.E]

Have you tried using these options?

Tangent extension

Ruled surface