Error on checkout (cart.php on line 675)

Get the following message:

Warning: Invalid argument supplied for foreach() in /home/fashiony/domains/fashionyouknow.com/public_html/administrator/components/com_hikashop/classes/cart.php on line 675

Warning: Invalid argument supplied for foreach() in /home/fashiony/domains/fashionyouknow.com/public_html/administrator/components/com_hikashop/classes/cart.php on line 675

Warning: Invalid argument supplied for foreach() in /home/fashiony/domains/fashionyouknow.com/public_html/administrator/components/com_hikashop/classes/cart.php on line 675

Please try to replace the code:
foreach($element->characteristics as $k => $characteristic){
$element->characteristics[$k]->default=end($mainCharacteristics[$element->product_id][$k]);
}

by the code:
if(is_array($element->characteristics) && count($element->characteristics)){
foreach($element->characteristics as $k => $characteristic){
$element->characteristics[$k]->default=end($mainCharacteristics[$element->product_id][$k]);
}
}

in that file and try again.