Was it mailed in late in the year?   If so, try using 0 as the AGI.   Returns filed late in the year may not have their AGI updated in the IRS Efile system properly.

Try zero, if not, print and mail your return.  Don't forget to also print and mail your state return if needed; in most cases, your state return is not transmitted if your federal return is rejected.  Make sure to check the status of your state return.

Some e-file rejections just can't be fixed even if your info is correct.