For some reason just the faces of the 3D character models I downloaded from the Marketplace are messed up, just during animations such as walking/idle. Non-animated meshes in their t-pose form are fine. Check out the image for what I mean. Thanks!
Are you sure the characters are made for the same version of the skeleton as your animations? They might not be skinned for your facial animations or the other way around. It looks like perhaps the skeletal mesh you have is expecting bones for facial animations, and you’re animating a skeleton that doesn’t have them.
Rigging, skinning and animations arent universal, they have to be made with eachother in mind. If you got the animations one place, and the character model somewhere else, there’s no guarantee they should work together.