I'm trying to run this code, and I get an exception:

Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index

private void LoadStudentGrades(int gradeParaleloId, int subjectId)
{
    GradeStudentRepository gradeStudentRepo = new GradeStudentRepository();
    students = gradeStudentRepo.FindAllGradeStudents().Where(g => g.GradeParaleloId == gradeParaleloId)
                .Select(g => g.Student);

    int i = 1;
    foreach (var student in students)
    {
        DataGridViewRow row = new DataGridViewRow();
                    
        row.Cells[0].Value = i.ToString();
        row.Cells[1].Value = student.LastNameFather + " " + student.LastNameMother + ", " + student.Name;

        dataGridView1.Rows.Add(row);
        i++;
    }
}

I manually created the columns in the datagridview, and now I would like to populate the fields using this small method.