Hi,
Please try to access the URL:
onzekralen.nl
You will see that you will be redirected automatically to
onzekralen.nl
(the non SSL version)
So it means that you configured your website, either via a htaccess or the apache configuration to redirect SSL requests to http://
When you access the checkout, HikaShop will redirect you to https://
Then, your htaccess or apache configuration will redirect again to http://
And to avoid a redirection loop, HikaShop won't try to redirect again to https://
That's why you think that this option doesn't work.