Incomplete Payment Issue | My form won't submit - it gets stuck on "Please wait".

The below form is for a conference registration and includes a payment field. Several people have attempted to register, but when they click "Submit," the button just says, "Please Wait" and doesn't end up submitting. We've only been able to get two people to successfully register. Please advise ASAP on this time-sensitive matter. 

FYI - this has occurred on Chrome, Firefox and Internet Explorer for people in various states. 

Hello,

I cloned your form to my account and tested. It is working properly. The issue belongs to submissions with Incomplete Payment.

If the user doesn't complete the payment when the PayPal is redirected, you should look at the Incomplete Payments page on your account:

You have one incomplete payment waiting and it is a test submission.

I also logged into your account and tested your form from your side. My submission also marked as Incomplete since I didn't continue to PayPal Payment:

In addition to that, when a user leaves his payment as incomplete, the submission can be viewed as Incomplete Payment, but the notification and auto response emails are not sent. You can complete the submission on Incomplete Payment page after, while screening Incomplete Payments. After that the emails are sent:

I hope this answer helps, if you have further issues please contact us again.

Good Luck!

Hello again,

I forgot to ask you that if you use the form embedded to a web site? If this is the case please supply us the web site that contains the form if the above suggestions don't solve your issue. 

Thank you.