1. Shopping cart is empty after adding products or items to the cart ( happen to Google Chrome only and it only happens to some user)
Solution: when browsing with Google Chrome please use "Incognito Mode"
2. How use coupon code?
Solution: Go to Checkout/Cart and look for "USE COUPON CODE", if the code is active and correct, you will see the details like.
3. Why some code is "Coupon is either invalid, expired or reached its usage limit!"
Solution: Try to sign in and use the code. Some coupon code require sign in in order to use.