Confidential Questionaire - Hit Submit button and "error" occurs

Over the past few months, clients get to end of Confidential Questionaire form >> click submit >> "error" pops up with no way to resolve.  Then forces client to start again and it takes 20 minutes+ to complete form.  

Yesterday - Laddie Fromelius, laddiec2@gmail.com just let me know via email he had same issue.  Can you see anything on your side?  I have no notice until form is completed

Suggestions?  

Thanks, Scott   

I cloned the form to test it and was unable to reproduce the issue.  Do you happen to know the specific error?  The form itself appears to be fully functional, is the form embedded to a web page by any chance?  Let us know what you can and we will be happy to investigate further.