I'm flying the TUTORIAL from EGLL to LSZH. The FL in the tutorial must be 37000 feet, so that's what i entered in the FMC (FL370). Now I get this message? Somebody knows why?In my FMC flt plan it gives a 40500 feet as cruise level, but i'm flying at 37000 feet, because the tutorial said so. Optimum cruise level is 37500 feet is in the PERF of my FMC.

Check the weights are correct.... like I did you probably selected 2/3 and didn't notice that a bit more cargo is added. I did the same and left the ground like a rocket and moaned a bit on here.... that's when I found out lol so you ain't alone.John Ellison