Some partial animations cannot play as additive in Unity I am making a character in Blender and animating it through Unity's Animator Controller.
I have a Base layer in Unity which animates the basic body movements, and an Additive layer which animates the expressions.

The setup is working fine, but something is wrong with some of the partial animations. They get imported into Unity just fine, but will only play as Base-animations or Override animations, not Additive. As Override (when they are the only animations playing) they play just fine in Unity.

None of the bones in the expression-animations are referenced in the base/body animations and vice-versa.

At first I thought this was a Unity issue, but I fear it is my Blender animations that are to blame.

Anyone have any ideas or pointers as to why this could be happening?

Best,

/John
I had no luck getting the additive animations to work. Still have no clue why my head animation won't play as additive, only as override.

I ended up making an Avatar Mask and masked the character's body parts with it.

This way, my "additive" animations can play as Override. Not the perfect solution -- but a working solution.