ERROR: "Warning manifold obj nb:4 adj 4 of dim =2 freefem"

Hi everyone.
I’m writing a .msh file (“new.msh”) in order to get a new mesh starting from another one (I have to perform some local transformations, that’s the reason I’m writing a new .msh).

The fact is the following. The line

mesh Th = readmesh(“new.msh”);

does not lead to an error,


when I try to save the mesh Th


I get the error “Warning manifold obj nb:4 adj 4 of dim =2 freefem”

Could someone explain me the meaning of this error, and how is it possible a behavior like this ?

Thanks in advance.


This is not a error juste a warning so you mesh is strange !