It should work with space bar.
Did you tried to repair the game?
(Origin > Game Library > right click MELE > Repair)
(Steam > Game Library > right click at MELE > Properties > Local Files > Verify integrity of game files.)
It works with the spacebar in ME1 and ME2 LE, but not with ME3 for some mysterious reason.
It was my problem six months ago; I uninstalled it, reinstalled it, and had to verify the files because of a bug in ME2, but it still doesn't allow me to skip with spacebar or any other button.
The problem persists; I tried to find out how to configure hidden hot keys in the game, but I don't know how to do it with ME3...
