The 76a_duplicate_make_local.blend has a group with an armature and a cube parented to the bone.
The 76b_duplicate_make_local.blend has that group linked and the armature proxied. The new armature grupo_proxy has an action.
- Open the file 76b_duplicate_make_local.blend
- Select and delete "grupo_proxy".
- Select group "grupo" and Ctrl-Shift-A, to Make Duplicate Real it. Check "Keep Hirarchy".
- Assign the previous action "grupo_proxyAction" to the armature "Armature".
- Try changing the frame through the timeline: the armature doesn't respect the action.
- Delete the empty "grupo" (it was the linked group): the armature moves.
- Save and reload the file: it moves.