RangeError (index): Invalid value: Valid value range is empty: 0

[saga009]

hello this code not working in my project it's given errors like :
RangeError (index): Invalid value: Valid value range is empty: 0
in this line :
var playerTrack = _playerTracks[0][0];
_safeSpots = [
playerTrack[0],
playerTrack[9],
playerTrack[14],
playerTrack[22],
playerTrack[27],
playerTrack[35],
playerTrack[40],
playerTrack[48]
];
please help what to do.