Can I downgrade to the free edition if I filed my taxes but they got rejected

[VolvoGirl]

If it doesn't let you clear and you haven't paid and filed you could just start a new account.  Online is only good for 1 return per account.  But you can use the same email address for 5 accounts.   Start another Online return here and sign up for a new account

https://turbotax.intuit.com/personal-taxes/online/

Or go to the IRS Free File programs

Free File: Do your Federal Taxes for Free | Internal Revenue Service