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I test submitted the form using its direct URL http://www.jotform.co/form/42177209228859
and I was able to submit the form without any error encountered
Can you plesae re-embed the form into your website using instead its iframe embed code.
Follow this guide: -Getting-the-Form-iFrame-Code
Make sure to remove first any previous existing embedded script code of the form in the webste before you use the iframe embed code. This is to make sure there will be no conflict on the web page.
Let us know if issue persist even after doing this already.