Configuration of Hikashop is displayed incorrect

-- url of the page with the problem -- : www.wol-lokaal.nl
-- HikaShop version -- : 2.6.0
-- Joomla version -- : 3.4.5
-- PHP version -- : 5.4.45
-- Browser(s) name and version -- : Firefox

When i open the configuration of Hikashop in the backend, it's displayed as shown in the image. Anyone an idea what can be the problem?

Hi,

You have a PHP Fatal error in the configuration page.
Please check at the bottom of the page or in your PHP error log in order to get more details about the error.

Regards,