cart not updated?

-- Joomla version -- : 3.4.8
-- PHP version -- : 5.4.45
-- Error-message(debug-mod must be tuned on) -- : Message No cart found

I've tried almost everything, cache is off, using the t3 template where there is no other cache editing possible. I get the message in the popup: Product successfully added to the cart. But after i click the button: proceed to checkout, the only thing that happens is the following message: Message No cart found

The cart shows, but no product added to the cart. The wishlist has the same problem, also the link of showing the wishlists in the wishlist page does not show the wishlist, but the empty cart?

Hi,

Did you perform some tests after a "logout / login" ?
I do not have any account in your website but I was able to add a product in my cart as a guest used.
pasteboard.co/UlK3uQE.png

You can have an issue with your user session ; but you can also have some restrictions.
By deactivating temporally the "popup notice" and just stay on the same page or redirecting to the checkout : you will be able to see error messages.

Regards,