Solid difference not working

Hi everyone! Does anybody know why this solid difference won’t work? I am trying to obtain the red curves as a result, and I tried with region difference too, but It won’t work either. Thanks!!

solid (1.6 MB)

Your two trees of curves are unmatched.
The two data-tree are differently sorted)

You should probably re-check how those curves were created…

Hi! thank you for your answer! What do you mean with how they were created? And how do you think I shoud sort them out?

I suppose this complex data-tree structure was created in grasshopper.
Well, the two trees do not match.

I think the best would be to directly create the two trees with the same structure… if you can’t… maybe you can re-sort them by a search by distance (the closest) (after scaling by Z…)
But it’s 03:30 AM here… sorry…