Customers are not able to checkout due to this error. Any help in solving this would be much appreciated:

Warning: strstr() [function.strstr]: Empty delimiter. in /home/nilajah/public_html/includes/modules/shipping/zones.php on line 230

Warning: Cannot modify header information - headers already sent by (output started at /home/nilajah/public_html/includes/modules/shipping/zones.php:230) in /home/nilajah/public_html/includes/functions/functions_general.php on line 44


TIA!