WIDGET shopping cart ERROR warning = 249 3 - LIVE SITE

newest update..
2.9.4.3

Add more than one item to shopping cart.
shopping cart Widget in sidebar..

get this error FRONT of SITE for all to see.

Warning: array_sum() expects parameter 1 to be array, null given in /home/site/public_html/wp-content/plugins/marketpress/marketpress-includes/template-functions.php on line 683

Warning: array_sum() expects parameter 1 to be array, null given in /home/site/public_html/wp-content/plugins/marketpress/marketpress-includes/template-functions.php on line 683