I know you can use Asset → Remove Unused Bones From Skeleton, but it still keeps bones that I don’t need. Is there a way to truly remove old skeleton asset and update it with new one? Also I tried to use replace asset, but it crashes during the process.
I found the issues. It was because there were other skeletal meshes that were sharing the same skeleton asset. You would have to remove the unwanted bones from all meshes that shares same skeleton in 3d sw package and re-import fbx file. I was able to remove all unused bones after I have done that.
