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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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How can I fix the 'Not Found' error?Asked by jrowley on January 18, 2016 at 06:12 PM
When people submit a jotform, it shows them an error saying that the page isn't found. We receive the jotform, but the clients don't realize it. Please help us fix this error. Thanks.
not found error
I think you have figured this out already. The error is related to your custom thank you page URL which doesn't exist your website;
If you want to use a thank you page, make sure to create it first to your website.