Hello all, my first post here. I’m having trouble with a polycurve. I’m trying to create a section from the points as shown in the screenshot. The result should be as in the second screenshot. However, using the 2nd method I get the error that the shape is not closed and I cannot loft these cross sections… Hence I’m trying the polycurve, but to no succes… It seems to me as if it using the wrong plane, but I have no idea how to set the working plane to YZ for example… Anyone have an idea? 
Maybe try polygon.bypoints
Can you show the data preview of the first and second method? Also it helps to try disabling all previews and working on a single sub-list so you know you have the data stream correct.
@Simon, I tried the polygon by points too, but it creates only two lines. See screenshot
@Jacob
These are the datapoints used with the different methods… Somehow it refuses to go down in the Z-axis and only connects in the X/Y direction.
Can you post a recreation of a portion of the data set?
If you run a different command does it work on all points? Maybe try a sphere by radius centerpoint with an array of color to visualize if you have overlapping points or if there is something wrong with them.