There are those who got the advanced child tax credit in 2021 based on their 2020 return but are not claiming a child on their 2021 return. It usually involves divorced parents who alternate claiming a child. So the program is checking for a tax payer who received advanced child tax credit in 2921 but is not claiming a child in 2021. In that case some of the credit might have to be relayed. If you tell the program that you lived in the US more than half of the year and you didn’t receive advanced child credit you will clear the error.
