Hello,
I have both pdf invoice and pdf datasheet addons installed in my ubuntu test system.This error appears when using either (FPDF error: Some data has already been output, can't send PDF file).
Have noticed other people with this error but have not found a cause.
I have searched includes/aplication_top.php for super tracker but does not exist.
I have checked pdf_invoice.php script for errors.
This is not a clean istall of oscommerce v2.2 I have other contribs within admin which could be affecting.
Any Ideas?