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 am not sure if I have understood your question correctly.
Do you mean to say that some validation errors are triggered in your form but you can't find which form field has triggered it?
I did test your form but I am unable to replicate the issue you are having. I filled in the required fields of your form and I was able to submit it successfully. I was redirected to the PayPal checkout page.
Have you embedded this form in your web page where you are getting this issue. I would suggest you to please share your web page URL and we will take a look. You may also like to share a screenshot of the problem so that we can understand it better. The following guide should help you upload image in your forum post: http://www.jotform.com/answers/277033
We will wait for your response.