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Why do I always get the following PayPal error page when I try to pay using
PayPal for Sandbox items?
This function is temporarily unavailable. Please try your payment again later by returning to eBay and clicking the My eBay button.
After registering a Sandbox user with the eBay Sandbox User Registration, you need to modify the registration and Shipping Address and fill in a correct address, otherwise you will see the above error message when trying to pay using PayPal.