We have a file (FBX or OBJ) from which we import skinned meshes and their animation. From that file, we create a prefab, on which we add a collection of scripts. Our issue is simple; if we add vertices or have a vertex skinned on a bone it wasn't previously skinned on, there's the chance the prefab would break down and not properly be animated. We tracked down the issue to this; - When you import a skinned mesh, the BoneWeight structure uses indices that are link to the list of bones in the SkinnedMeshRenderer component. - The SkinnedMeshRenderer "bones" list does not references all the bones in a skeleton, but only the one the mesh is using. - If the mesh is updated to target another bone, the SkinnedMeshRenderer list of bone in the prefab is obviously not updated. Which means the BoneWeight suddenly targets the wrong transform, or no transform at all. Have you ever reimported a skinned mesh just to find that it broke down in a prefab? Is there a work around?