Pre-mesh: missing surfaces
 

Hi,

I attached two pictures which show my issue.
When the pre-mesh is created, there are missing shells. My blocking seems good, so I don't understand where it comes from.
Any help is welcome ;)

Thanks,

Face to part
 

There is probably another surface very near by, but in a different part... the premesh is reaching the one surface just before the other (it may be 0.000001 closer in some spots). There are shells there, but they are in the different part. Since you have turned that part off, they do not appear.

If it is just a duplicate part, you can probably remove it. If it is the boundary of an adjacent volume and you just want this mesh to be in a specific part without removing the other part, You can force association of those faces to the specific part...

Blocking tab => Associate => Associate Face => to part.