The current CAS mesh is not compatible with CAP and every time I try to replace CAS without replacing CAP my game crashes what is the error in the modl resource thanks in advance

The meshes for Create a Sim, Create a Pet, and Create a Plumbot cannot be separated. The way they work is with a geostate that switches what parts of the meshes are visible.
You would have to be familiar with working with geostates to safely modify one part- making an empty room for someone has been on my to-do list for a while, but until then I don't think anyone has looked into it in more detail.

It's likely crashing because it's trying to read geostates that are no longer valid, and practically exploding the mesh on loading CAS.
The MODL could also be a culprit, as the original contains the higher detail meshes in separate mesh groups but the one in this package is just a few triangles.

I knew all this, but when I replaced cas, I replaced all the rooms, and I wanted to replace only “create a sim” and the problem as I understand it is that the new meshes “create a sim” is one image and “create a pet” uses a composite an image that is divided into fragments, separate walls, separate floors and ceiling, and the game crashes therefore.
Thank you.

Without any context for what process you went through making this package, I can only offer what I know about the topic in general

This is uncharted territory, as far as TS3 topics go. As far as I know, the only manual geostate documentation that exists was written by me and it was so niche it hasn't really had the chance to be tested and improved on
This just means some of the troubleshooting and solutions may have to be done yourself, as what works and what doesn't hasn't been documented.

What I do know for sure:
It is the MODL, not the MLOD, that is causing the crash. It needs to contain your high detail mesh for all three rooms.
The exact relationship between the MODL and MLOD meshes for the CASRoom aren't fully understood yet- the low detail mesh is never seen ingame, afaik.

If you delete the string with the SKN resource, and the corresponding 'bone' hash, there game will be no crash, but the CAS mesh will not work.

Likely because that's a bone assignment that this object didn't (and shouldn't) have. Was this mesh modified in TSRW at some point? I don't think that program can handle a special object like this without giving it data it thinks a buy mode object should have.

I don't know what manual changes you've made to the mesh data, I also don't know what tool or method you are using to do so, but it has caused the issue. I would start with a fresh copy of the original MODL and narrow down which mesh groups are pieces of CAS, then focus only on repurposing those groups for your new mesh. Any extras can be replaced with an empty group, if need be, which is a safer place to start than trying to mess with the data directly
I would not use anything other than S3PE, Milkshape, and Blender for this process.

I informed the creator, that the current mesh is causing a crash, when used her with EA CAP mesh, the creator will return to the project, as soon as he solves personal problems.