Fatal error: Call to undefined function: str_split()

For people who are using still PHP 4.x, you can add following function at end of the file:

if(!function_exists('str_split')) {
  function str_split($string, $split_length = 1) {
    $array = explode("\r\n", chunk_split($string, $split_length));
    array_pop($array);
    return $array;
  }
}