bf 109 engine stop running during flight

[U505]

I was playing the desastersoft campaign when its engine stops (i don't know why) and it was unpossible to restart it again ..the magneto was on the lowest position.i push it upwards and then when i push on the I key to restart the engine a message appears on my screen "stop the engine".Does anybody have the same problem and how did you manage to restart the engine? thanks in advance.