I found the solution to this after contacting support and getting on with their tech support.
The suffix field on my Iowa state return is what was the error issue that would not let me e-file.
The solution:
Go to your Federal 1099-DIV entry screen that lists out all your 1099-DIVs. Edit each one so that the Payer field is only 15 characters or less. That should fix the problem and not give you the Suffix error.
