Thank you but the problem is when it is corrected the error doesn't go away and won't save the item.
I'm using Nintex 2013 in onPrem (in case this may be an issue).
I do see on your screen there is another error on a different field 'This is a required field'. Do I need to add a 'dummy' field following for continuation of the check?
Not necessary. That is a title field which is set as required in the column settings. I just put to check the validation rule.
If you dont have many controls, Can you delete the form and try it once again?
check for any errors in developer console.
what formula have you used to display names in 2nd row?
if it should display just values of name control it would look differently.