Issues Creating Surface w/ Grasshopper

So I’m trying to create a surface from contours. Initially, I tried patch but it wasn’t as accurate as I liked. I followed a youtube tutorial and was successful until I ran into “1. A point in the grid is null. Fitting operation aborted.” Apparently, I need to untrim but that is not possible. Any help with this problem would be greatly apprecieated.

GH file
Rhino File

it looks like a number of points that are being projected do not find any destination mesh on which to project along the ray direction:

maybe using curves from a bigger portion of terrain would solve this: the important thing is that all points can find a mesh along the direction on which they are being projected

Ok I will look into this. Thanks you so much!