The red curve is just twice the size of the green, but _Curvature cannot find its maximum curvature point.
CurvatureFail.3dm (24.9 KB)
Also, RhinoCommon’s Curve.MaxCurvaturePoints fails (returns None) for the red curve, but not the green.
This occurs in V5, V6, V7.16.22067.13001, 2022-03-08, and the WIP.