I recently (November 2017) updated my Recalbox (through the built-in update function) which so far had always worked fine. But now, I cannot launch any game. They are still all on the systems lists, but when I select any of them (I tried many different systems), the screen turns black (like it always did before displaying a game), hangs for around 10 seconds, and then gets back to previous menu. The Recalbox does not crash, it simply acts as if I had decided to exit the game.
Needless to say, I did not update any of my roms, which always worked prior to the Recalbox update.
Thanks for your help.