Need help! New mesh do not replace old mesh in S4S.

Sorry for the delay. When you clone a necklace you will often see that the mesh has two parts--the necklace and a small cube hidden inside the body. Your blend is missing the cube, which needs to be there in order to import the mesh properly. In your blend the cube should be s4studio_mesh_2 (cut 0000), and the necklace should be s4studio_mesh_1 (cut 0001). Your new mesh always has to have the same number of cuts as the original cloned item.