The loop button will bring the display to show the looper config. IMHO this is all it does.
To record a loop you need to press the play button twice. At first the looper will start (button is green), then it will start recording (red). Press the button again (or stop), to stop recording.
Patrick Craig Manning
I just got the erae2. Everything is super on it, but I am trying to figure out how to use the loop button. It doesn't seem to do anything with any of the screens I have set up.