Hi ! 
   	  
   	I have tried to build faces from the geometry menu and I have the error : 
   	Geometry is not correct and must be corrected. 
   	  
   	What can I do ? Why this error ? 
   	  
   	For information, I am trying to follow the tutorial of the example MagnetoThermal in 3D. 
   	  
   	Thanks in advance.