Meshpatch doesn't work


a couple f weeks ago I build a topography from couture lines elevated them and used Meshpatch to create a Mesh. It took about 15min.

Today I rebuild the same Contour lines and tired Meshpatch. After 3,5 h nothing I tried many different methods. the only thing that some what worked was exploding the curves and using the vertices and Delauny Mesh command to create an invalid mesh.

what did I do wrong ?

When I divide it into smaller subdivisions its not an issue to create a mesh how ever if I try to Meshpatch the entire thing it wont work even so it work a few weeks earlier?
Coutourlines_topogrphy.3dm (3.7 MB)

See if this gets you sorted:

OO damm thx.
Why des that work better then using the lines ?