Hi,
Change the code:
$values = array_merge($values);
JArrayHelper::toInteger($values);
$query = 'SELECT warehouse_id, warehouse_name '.
' FROM ' . hikashop_table('warehouse') .
' WHERE warehouse_id IN ('.implode(',', $values).') '.
' ORDER BY warehouse_name';
to:
JArrayHelper::toInteger($value);
$query = 'SELECT warehouse_id, warehouse_name '.
' FROM ' . hikashop_table('warehouse') .
' WHERE warehouse_id IN ('.implode(',', $value).') '.
' ORDER BY warehouse_name';
in the file administrator/components/com_hikashop/classes/warehouse.php and that should fix the problem.