When did you file 2017? If it was late in the year try putting in zero for the AGI. And see this, https://ttlc.intuit.com/replies/5595742 If you can’t get it to efile you will have to print and mail it.
How to correct the AGI https://ttlc.intuit.com/replies/4168567
if trying your agi from 2017 return or $0 doesn't work, you can check your 2017 number by going to IRS website and looking at transcript. if that doesn't work, your only recourse is to paper filing. make sure to use a method where you get proff of delivery.