impossible to create single loft

[Nespy]

you are one of my last beaches!!! you are all very experienced users and therefore I enlighten you my problem:
I can't make a single loft on the territory I have to represent, if I try to do it on 2 polylinese only (but it always depends on which) it manages, while in other cases it tells me that it is impossible to carry out it
are all closed polylines brought to its quotas.
the program in processing very often does not respond. . .
is a job for an exam and nn so + where to bang the head...

thanks in advance I also attach the file

 

[lattu]

creating a loft of certain dimensions sometimes is impossible.
Do you have to get a solid or would you like a set of surfaces?
would be more laborious but surely feasible

 

[alesky72]

I agree with latu: a single loft is too complicated for autocad..
I to create surfaces or solids of land use some applications (such as dtm and terraincad) that always turn under autocad but that give you additional commands: I train you what I managed to get from your dwg:smile: