There are issues with switching the blend model to the rest state

[Evgeni_Popov]

It could be a problem with incompatible skeleton. See this answer from @PatrickRyan, and also his other answers in the thread:

The skin of different skeleton animation from the same model is incorrect

@xiaopangoo, this looks to be an issue with the joint orientations not matching between the skeletons. This is the orientation of the upper arm from the broken skeleton with Y down the bone: [image] And this is the orientation of the working skeleton with X down the bone: [image] If you are trying to retarget animation or skeletons between meshes, the skeletons need to be identical down to the rotation of the individual joints. I hope this helps!