I couldn't solve the problem after my last message. I think I probably made a mistake in choosing the mesh. Can you please help me with this? The structure is as follows:

1- Glass is used as substrate
2- Polystyrene spheres are placed on the glass.
3- The surface with these polysterene spheres is gold plated. In order to do this in the simulation, I added another sphere on top of the polystyrene spheres and obtained nested spheres.
4- Finally, there is a gap between the spheres on the glass. In order to fill this gap, I covered the entire surface with a golden structure on the glass.

I am attaching the side and top view of the design I mentioned as a picture. Please here;

2-Polysterene spheres
3- Au sphere coatings
4- Gold plated on glass substrate

Can you tell me what should be my mesh order for structures? Also, what boundary conditions should I choose?