Hello.
I've been working with this opentype code for OldStyle Figures.
But when I try to make the otf file I've got this error.

This is the code:
@onum2 = [zero.oldstyle one.oldstyle two.oldstyle three.oldstyle four.oldstyle five.oldstyle six.oldstyle seven.oldstyle eight.oldstyle nine.oldstyle];
@onum1 = [zero one two three four five six seven eight nine];

# Old Style Figures
feature onum {
substitute @onum1 by @onum2;
} onum;

The error:
makeotfexe [FATAL] invalid token (text was "") [features 23]

makeotf [Error] Failed to build output font file tmpyRjUC3.otf.

Thanks!