Blender 2.77 still has this problem - it adds ‘Armature’ bone on top of hierarchy. For example, if I get a character from Mixamo, import into Blender to adjust skin weights and then export, it’s no longer compatible with Mixamo rig, because of this ‘Armature’ bone (‘FAILED TO MERGE BONES’ error). I set ‘ignore leaf bones’ and it doesn’t add these leaf bones, but still adds the ‘Armature’ as root.
Is there any way to delete it? It doesn’t let me to select it in hierarchy and delete it…
I will try Blender 2.78 soon, but I’m afraid that it’s not fixed there.