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.
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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.
Hello Irene, can you double check the File Type extensions allowed on the File Upload field? It's also a good idea to double check the File Size limit while you're at it.
Since you never mentioned what form you're working on, I tried my luck by manually typing in the address I saw on the screenshot you sent us. However, I failed to load the page (perhaps it's just viewable from your company's end).
We can better assist you if we could take a look at the actual form you're currently working on. Just share us the Form URL/ID or website/page URL where you have it embedded. In the interim, try the guides I sent first then get back to us if you need more help.