It’s working now but I didn’t change anything 😉
I tried another time and… it works well : no problem at all to the main menu.
Now another little problem : when I click to load my savegame, it freezes for ~30 seconds (music from the main menu still playing), and then another music starts (I guess it’s when the save game is loaded, but it cuts the previous music), a few seconds more of freeze, and then the map appears : it’s the nightmare for 1 minute (3-4 fps) (I guess it’s for the loading but… I only have a few coaches and a train !), and then the fps are raising to a normally state (~60).