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.
The Jotform tab is working so I guess you are experiencing a browser related issue. I would suggest the same, try to logout from your account re-edit the form. See if the button still won't work after. If not, check it with another browser.
Lastly, check your browser console for related errors. Take a screenshot of the whole console area and upload it here. You need to access this thread to upload.