using version 1.3.7 I get these errors when trying to complete a purchase:

Warning: reset(): Passed variable is not an array or object in /home/content/s/t/e/s/html/includes/modules/order_total/ot_group_pricing.php on line 77

Warning: Variable passed to each() is not an array or object in /home/content/s/t/e/s/html/includes/modules/order_total/ot_group_pricing.php on line 78

Warning: reset(): Passed variable is not an array or object in /home/content/s/t/e/s/html/includes/modules/order_total/ot_tax.php on line 38

Warning: Variable passed to each() is not an array or object in /home/content/s/t/e/s/html/includes/modules/order_total/ot_tax.php on line 39

Warning: Cannot modify header information - headers already sent by (output started at /home/content/s/t/e/s/html/includes/modules/order_total/ot_group_pricing.php:77) in /home/content/s/t/e/s/html/includes/functions/functions_general.php on line 44