Error notice on product detail view in back-end

-- url of the page with the problem -- : kaasboersterk.nl/nieuw/administrator/ind...ikashop&ctrl=product
-- HikaShop version -- : 3.0.0
-- Joomla version -- : 3.6.5
-- PHP version -- : 7.0.16
-- Browser(s) name and version -- : Chrome 56.0.2924.87
-- Error-message(debug-mod must be tuned on) -- : Warning: ksort() expects parameter 1 to be array, null given in /var/www/vhosts/kaasboersterk.nl/httpdocs/nieuw/administrator/components/com_hikashop/views/product/view.html.php on line 1896

Warning: Invalid argument supplied for foreach() in /var/www/vhosts/kaasboersterk.nl/httpdocs/nieuw/administrator/components/com_hikashop/views/product/view.html.php on line 1897

Hello,

I noticed these notices in the back-end. Is this a bug?

Cheers,
Teeuwis

I also noticed this error with another product:
Notice: Undefined property: stdClass::$sorting_value in /var/www/vhosts/kaasboersterk.nl/httpdocs/nieuw/administrator/components/com_hikashop/views/product/view.html.php on line 1898

Ok, thanks!