Object reference error when importing new mesh

Cut numbers are the reason it is not importing, but there is no point in getting it in s4s yet, since the frankenmeshing process is not done right

Clone this maxis blazer again, export the blend, open it.
Each of these meshgroups has only two uv maps, named uv_0 and uv_1;
If you were to open uv_0 in the uv editor, you'd see that all uvs are in the space meant for tops.
And all parts of the mesh are rigged and vertex painted.
To function in ts4, your garment must be adapted the same exact way: split the same way in the same number of meshgroups with corresponding cuts, have only two uv maps named uv_0 and uv_1, have uvs in uv_0 be in the space meant for them, receive weights, uv_1 and vertex paint from a maxis item.

You need to watch a tutorial on combining multiple maxis meshes into one ( frankenmeshing) to get a better idea of what your end product should be like. Then you could watch a tutorial on making accessories for ts4 from scratch to learn how to add a heart

Overall idea is like this:
- remove unwanted parts from a blazer;
- append a skeleton, remove unwanted parts from it;
- create a new uv map for a skeleton;
- select a blazer, then the skeleton, re-arrange skeleton's uvs ( they go into the space for tops, without conflicting with blazer's uvs), rebake textures, save;
- once done, duplicate uv_1, delete uv_0 and uv_1, rename remaining uv maps to uv_0 and uv_1;
- in this order: select the skeleton, then Ctrl-select the part of a blazer that had a shirt, join;
- now you import the heart, transfer weights, uv_1, vertex paint from the skeleton+blazer, rename a uv map to uv_0;
- put uvs in uv_1 where they wont conflict with the rest of the garment, then join both ( again, the hear first, then the blazer )