Cannot modify header information - headers already sent by ,,,

[mc12345678]

I downloaded notepad++ and glad to see the line numbers, this will be very helpful to someone who knows nothing about what they're doing.

line 515 of fedex is

echo '<!-- ' . $this->fedex_shipping_weight . ' ' . $this->fedex_shipping_num_boxes . ' -->';

so I'm still in the dark.

line 514 =

case (2):

On that line but at the beginning add // as below:

// echo '<!-- ' . $this->fedex_shipping_weight . ' ' . $this->fedex_shipping_num_boxes . ' -->';

Try again and check the error logs to see if anything else is wrong. :)