Hi Karsten

Finally found the simple error.
Line needs to be replaced with Curve, twice

Line.title = "Curve";
Line.desc = "Curve";

ICurve.title = "ICurve";
ICurve.desc = "ICurve";

- Brian

I renamed it ICurve, because ControlPoint curves are also possible.

Now I will try the simple Catenary to feed into ICurve.