JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
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 have tested Form Designer on my account and it is working.
Please try to clear your form cache.
Also you can try using different browser.
Hope this will help. Let us know if you need further assistance.