In FLine.HasIntersection, when a null intersection point is returned from the Intersect function, the subsequent line will throw an error.

The issue is that most of the times sketcher cannot make an intersection of complex surfaces built from B-Splines with sketch plane. In test example there is gordon surface, but I've seeing same issue ...

I've started working a personal program to design shapes with tubing (and produce G-code for a CNC tubing cutter I'm going to build). It's been roughly 20 years since I was last in a vector geometry ...