If nothing below works, you can always print, sign, and postal mail the return as a last resort. NOTE: If you choose to do that, YOU have to mail it; TurboTax does not mail it for you.)
Be sure you are using the 2017 AGI from the original 2017 return, not an amended one.
If you filed the 2017 return real late in the year, such as November 2018 or later, you can try an AGI of 0 (zero.)
If the 2017 is a joint return, both spouses use the same 2017 AGI. Do not divide or allocate it.
If you qualify to open a free IRS account, you can download a 2017 return transcript to check the 2017 AGI in the IRS database. If you can't open the account, you can order one to come by postal mail in 5-10 calendar days.
http://www.irs.gov/Individuals/Get-Transcript
Also see this FAQ:
https://ttlc.intuit.com/questions/3415597-what-if-i-entered-the-correct-agi-and-i-m-still-getting-an...
If you end up trying everything and still are getting rejected, if it was me, before filing by mail I'd try one last "Hail Mary" attempt and see what happens with an AGI of 0 (zero.)
