Users of my form are unable to submit once complete. Please help.

When anyone uses my form, the "Submit" button never appears. The only option is "Preview". This form is new and has not yet been used by my target audience, but it was cloned from a nearly identical form that we've used in year's past. To try and troubleshoot the problem I returned to the previous 2 year's forms (which have not been edited since last successfully used) and I experienced the same problem. 

Please advise asap as this form has already been released to my audience and our deadline is approaching.

The reason for this is because you have two preview before submit widgets.