Client says “proceed to checkout” empties cart and returns to homepage
A customer would come to the website, place items in their shopping cart, and then click the “proceed to checkout button” from the shopping cart. Rather than take them to the cart, our Magento website would immediately forward them to the home page and empty all the items from their cart.
Cause: ISPs like AOL, Comcast, and Shaw.ca use a technique of changing IP addresses that cause security settings in Magento to empty the cart and not allow people to check out.
Fix: Change the Session Validation settings in the Magento Admin, found under System > Configurations > Web, to ‘no’ on everything except “Validate HTTP_USER_AGENT.” After doing this, go to System > Cache Management and refresh the configuration cache to apply the changes.