Sad news this system not working with 3.0 version: Ok, I fixed the problem, doing the same as the post creator. You gonna need to replace  the .cfg file you just saved as retroarchcustom .cfg. For whatever reason the retroarch will alway load this file and not what you just saved. To do this you need to: 1. Download and install WinSCP 2. Get yourself connected to your recalbox (heres a tutorial in french, you can trasnlate it using google like I did, just care so you won’t traslate the username and password. https://github.com/digitalLumberjack/recalbox-os/wiki/acces-via-WinSCP-(FR)</p> 3. In WinSCP go to       /recalbox/configs/retroarch 4. You better do yourself a backpup of the retroarchcustom.cfg and save it on you pc. After that go on and delete it so you can rename the .cfg file you did inside the game when trying to configurate your controls. Rename it to retroarchcustom.cfg and it’s done. In my I renamed pocketsnes_libretro-1.cfg to retroarchcustom.cfg. Enjoy! , retroarch make a one new archive call retroarchcustom.cfg and  overwrite the last one. I cant maping the buttons of  my arcade machine now. you can help me?