You kinda seem offender with my statement for some odd reason, or at least thats the energy those reply come in for haha.

Regardless I ment I just open the unity project, and started uploading to the project each component and left the legs for last.

Putting the components through CC before opening unity, adding the avatar, the legs, ect, wouldnt work.

So i just decided to just open a clean Project with nothing but the SDK and upload 1 by 1 in the order the creator page showed the requirements.

Using these exact files I redownloaded after deleting mine off my PC (I didn't feel like waiting a million years for Booth to give me my files), I got a perfectly working Manuka and Lasyusha out of it.

This is from a couple of weeks ago, same packages in both projects, the versions being slightly outdated shouldn't affect it.
FINal IK is missing from here because I forgot to add it, so I added it afterwards with a unitypackage, but that does not make a difference in this case.
The only other thing I've added that's not on this list, is GoGoLoco (works surprisingly well with the legs if you're feeling like being a deskie spider, little tip for people reading this), but that doesn't change anything about the functionality of the asset either.

So if you're sure you used both the character-specific package, as well as the commons package, and you're using the correct prefab, then there must be something else in your project that's interfering, or you didn't actually attach it to your avatar maybe but put it slightly too low in the hierarchy? I don't know!

Those are the packages on my CC

and i added these https://github.com/nekobako/MaskTextureEditor?tab=readme-ov-file
https://hellojingai3d500.booth.pm/items/2946865

Based on the author post on Booth.
But

Besides the shader, the Modular Avatar is having issues merging the 2