Null value after execution

Hi,
I am getting a null value in my output.
My GD is checking the visibility on the road.
I have attached my DYN and DWG files.
It’s a Civil 3D drawing.
My objective is to find the maximum radius that ensures visibility distance (maximum length of visibility Line in curve)
I have no problem in dynamo with the output.
Check

Is that the only input you have? Do you get nulls for every solution or just certain ones? Are you getting any outputs? Have you tried opening the graph in Sandbox to ensure that everything is cached correctly?

We need more context.

Also the DWG and dyn files don’t appear to have attached.