Problem with the method Rebar.CreateFromCurves()

I am getting an exception thrown from trying to create a rebar by curves; I would like some understanding to the cause, and idea for considering solutions to problem.

“Warning: IronPythonEvaluator.EvaluateIronPythonScript operation failed.
Traceback (most recent call last):
File “”, line 50, in
Exception: A managed exception was thrown by Revit or by one of its external applications