Note: At the time of writing, CodeGym is attaching the wrong task code (for task 2909, which has something to do with cars). I don't know why this is. Other questions on this help page are also showing code for task 2909 but the comments don't seem to reflect that, so I suspect it's a temporary glitch. For now, I will paste the code into the message as needed and leave out the attached part. The validation error: You need to change the Student class's incAverageGrade() method to use a setter and getter to access averageGrade. (You changed the behavior of the incAverageGrade() method.) So the problem here is that I originally thought this step said to remove the incAverageGrade() method and replace it with a setter. So I have to create a new incAverageGrade() method trying to remember what it used to be. I assumed it just added 1 to the averageGrade. Unfortunately, what I remember is wrong. See the code for my attempt at the method here, and please let me know what the original method was, I can't remember.
public void incAverageGrade()
{
    setAverageGrade(getAverageGrade() + 1);
}