What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
I was not able to replicate the issue that you are experiencing. I did a test submission on your form and was taken to PayPal without an error.
If you are still experiencing this issue, please remove the Payment tool from your form and add it back once again.
I hope this helps, please inform us if you need further assistance.