Hi everyone, I have an issues with beard shape keys, they simply doesn't fit to the head deformation as you can see below, the morph "Mouth Up" deform the beard to the Left instead.
Does someone know something about it ? (It seems to work well in cc4 so I'm guessing there's a renaming issues when exporting to blender)

I can't reproduce this.

Have you tried re-applying the CC4 Extended facial profile? Template : Item : All > Character > FacialProfile > CC4 Extended

The CC4 standard profile doesn't have the Mouth_Up or Mouth_Down expressions, so if the CC4 exporter incorrectly indexed the standard profile with the extended profile names then Mouth_L (Which is the expression shown in your Blender screen-shot) would be incorrectly labelled as Mouth_Up. Re-applying the facial profile might fix it.

Worked like a charm thanks !