Any reason what seems to be a perfectly good curve would turn into a null when passed through a ModelCurve.ReferenceCurveByCurve (or a ModelCurve.ByCurve) node it throws a null on tow of the curves. From the image you will notice that I actually have two groups of curves and this does not happen on the other group. I have also not had this problem when running it on other surfaces. Any ideas?
