I got an armature with 2 actions created with it. Then I appended from another file an action belonging to another but identical rig with identical bone names. I cannot bring this action to the same slot. What should I do?
Hi,
I am not sure if this what you want to do, but here is a little demo of what I think you wanted to do haha 
Thank You very much for Your effort, but I don´t understand this until now. I´ll try to make a little video for better demonstration of my problem
Maybe wrong, but at the moment my gut tells me what you are likely trying to do (or at least the result of what you want), is what the just started Blender dev work on of Layered Animation will provide.
Well, its a plan, but not a thing at the moment, the development for layered animation only just started. So there’s no default Blender version with it right now.
Hence, I think the only option would be as shown, to cut and paste all the keyframes, which would give the 1 object and 1 slot, but also 1 action. Basically forever smashing all the animation together.