If you filed late or amended your return, your correct 2017 AGI may not be in the system.
If entering the amount from your 2017 tax return does not work, then try entering “0” instead. If that does not work and you still cannot e-file, then print, sign, and mail your tax return.
https://ttlc.intuit.com/questions/1944348-how-do-i-print-and-mail-my-return-in-turbotax-online
