Mesh shows in S4Studio but in CAS only the texture (solved)

Hi. Many outfits are made from multiple meshgroups to interact with accessories and shoes properly. Cut numbers are what Sims 4 Studio uses to determine which mesh group in your .blend will be used to replace an EA mesh group in the original LOD.
Basically you split your outfit wrong.
Instead you can simply
- delete s4studio_mesh_2 and s4studio_mesh_3 by right-clicking on them in the outliner and choosing Delete;
- select s4studio_mesh_1, click on the tiny + icon in the bottom, type b__ROOT_bind__, select it, click on that - icon to the left;

- save, clone this dress, import your blend there

Keep in mind that your outfit is not uv unwrapped in the uv_1 map, it will not morph

As i understand, you exported the blend file of the dress I showed and merged it? Do not do this, you just need to start a package from it.
Open the blend you shared with us and do everything in the exact order without anything else, it should work because s4studiomesh_1 already has cut number set to 0000