https connection for choosing payment?

[Anypc]

I recently updated to 2.0.1k and now if I select the payment option I get an error message:

Not Found

The requested URL /index.php/webshop/cart/editpayment was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/2 Server at www.mydomain.nl Port 443

Somehow it goes to a https connection (https://www.mydomain.nl/index.php/webshop/cart/editpayment
I cant find the option to turn that off anywhere.

Anyone got an idea?