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've cloned and I've tested your form. I am able to replicate the issue you are having. When I clicked Next Botton, Your form was stopped working. I've check your source code. This issue is related with Form Tabs Widget.
Can you change the arrangement of your widget as you see below?
At that time, It will work more properly.
Here is how it works:
Hope this will help.
If you have any question or issues, please do not hesitate contacting us. We will be glad to assist you.
Considering that you last question is not related to subject of this thread, I have moved it to separate thread and we will provide you an answer there shortly.