Was the child under the age of 24 in 2023? If so and he was a full time student then you probably answered a question concerning him as a dependent incorrectly. You should have indicated that he lived with you for the Whole Year since he was a student. Also, make sure that when you entered his Social Security number you did NOT check the box not valid for employment.
You may just have to delete him as a dependent and then re-enter to solve this problem if he was under 24 in 2023.
