You are not actually required to file your 2017 Tax Returns before filing your 2018 Tax Returns.
If you go ahead and file your 2018 Tax Returns first, try using -0- for your 2017 AGI when you e-file them since the IRS has not processed a 2017 Tax Return for you yet. That *should* allow you to complete your e-file, even while your 2017 is still incomplete.
