We are seeing intermittent issues while submitting adaptive forms in AEM . Nothing happens when clicked on submit and does not redirect to thank you page though Thank you page is correctly configured on author.
Seeing below error in console when clicked on Submit.
VM12171:1 Uncaught SyntaxError: Unexpected token u in JSON at position 0 at JSON.parse (<anonymous>) at h (formapp.min.js:1) at s.doAjaxSubmitSuccess (guideRuntime.min.js:5221) at Object.success (guideRuntime.min.js:5214) at j (en.min.js:458) at Object.fireWith [as resolveWith] (en.min.js:476) at x (en.min.js:1151) at XMLHttpRequest.<anonymous> (en.min.js:1206)
As per the error message it looks like while calling JSON.parse function it's giving an error and as you mentioned that it's an intermittent issue:
It could be an issue with the data that is being passed from the form.
Please ensure you are passing all the requried data and proper data validations are in place.
Also please observe the data submission pattern, what is the difference between the data when one call gives success and other call gives the console error. This will help to identify the RC and will be able to resolve the issue.