Hi,
That's because you're trying you access an area of your website which is only available to users with a user account.
It has nothing to do with the fact that the checkout is configured to only allow guest checkouts.
So the problem is with the settings of the menu item you're trying to access. Either this type of menu item is not available to users without a user account, or you've actually configured the "access level" setting of the menu item to be available only to "registered" users.
It seems that you're trying to access the cart area. I would recommend you to change the type of that menu item to "HikaShop checkout" and configure the "checkout workflow" of the HikaShop configuration to have the cart at the beginning. It will be one less step for the customer and thus it will be better to have more sales.
www.hikashop.com/support/documentation/4...eckout-workflow.html