How to: fix InfoPath form error – “An error occurred when the form was being submitted’

Issue:

While Trying to submit an InfoPath form getting error – “An error occurred when the form was being submitted'

Resolution Steps:

• Found user has many fields and most of the fields are copied from other field so when we open a form in design mode found following error – Control stores duplicate data 

• At the first step of resolution I was suspecting this is the culprit behind this issue, and removed all duplicate fields added new fields and saved the form
• Republished the form and when clicked on Submit button got the same error.
• Again opened the form in design mode and checked following options in Form options Browser category

• All options were @ the right place.
• Then when I went to Submit options I was quite surprised because it’s a very small option I did not check and spent lot many time after this issue.
• Go to Tools > Submit Options > Manage > Modify

• Just checked “Allow overwrite if file exists” option.
• Saved the form and published it again and saw all is good.
• User did not check it because he was using a unique file name , he had manually written “Form” and he was afraid that if he this option is checked all form entries will be overwritten.
• So I have changed file name to user name field, so whatever user enters into that filed, The form will be saved with that name.