If you have not tried entering a zero for the 2017 AGI then do so now. If the IRS also rejects your federal tax return for this 2017 AGI then you will have to print and mail your tax return.
It would be wise to download the PDF of your tax return and the tax data file Now if you are using the TurboTax online editions since that edition will probably be shut down after today to make way for the 2019 online editions.
See this TurboTax support FAQ for the procedure to print a tax return for mailing when using the online editions - https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online...
