The payment worked, and the user was upgraded. Chrome doesn't show this message nor Safari.
2. Let's say a user has a subscription for 30 days. After 15 days in his/her subscription the user decides to upgrade to another month, so overall he/she has 45 days left. Is this possible?
3. How do I redirect a user to a thread after his/her purchase? Is this possible only with this add-on?
4. Is there a way to force PayPal to use a certain language in its checkout? (A language that is available in Paypal's interface).