CurvePlane() Bug?

[noclew]

Hi people,

Now I am trying to extract a curve plane using CurvePlane() method.
However, this function always returns None value when it come to the certain curve, which is actually planar polyline. (and when I check planarity of this curve using isCurvePlanar(), the result says the curve is not planar, although it is)
I spent a lot of time to figure out why with no luck..


It will be really appreciated if you can give me some help!
I simplified the code and also attach the curve that has a problem with CurvePlane().

Thank you!

import rhinoscriptsyntax as rs
curve = rs.GetObject("Select a curve", rs.filter.curve)
plane = rs.CurvePlane(curve)
print(plane)