We have tested our cart on a wide variety of platforms and browsers but different computers can have software that may create a problem. If a problem should arise, feel free to call us at 888-742-3404 or email webmaster@promolife.com. Please let us know where the error occurred, if you received any particular error messages, and what browser and operating system you are using. You can also order over the phone if you like. We will look into the problem and if it can be replicated we will fix it. By letting us know about an issue we can replicate, we will give you $5 off your order.