I use following code to display a custom ttf font:
ml.score = cc.LabelTTF.create(ml.totalPoints.toString(), \"fonts/American Typewriter.ttf\", 60); ml.score.
I made a mistake. The file name was wrong. It should be
ml.score = cc.LabelTTF.create(ml.totalPoints.toString(), "res/fonts/American Typewriter.ttf", 60);
Otherwise the code works fine. (shame ...)