If you are getting a rejection for AGI - this is coming from a mismatch between what is entered and what is in the IRS database. One way to be certain of the AGI that is in the IRS database is to request your IRS transcript. You can get a copy of your transcript here: IRS Transcript.
Getting the number from the transcript ensures that it hasn't been updated by any corrections or amendments that could differ from any copy of a tax return that you may have.