Джанго сигнализирует об иностранном

Question

model.py

class StudentsEnrollmentRecord(models.Model):
Student_Users = models.ForeignKey(StudentProfile, related_name='students', on_delete=models.CASCADE, null=True)
School_Year = models.ForeignKey(SchoolYear, related_name='+', on_delete=models.CASCADE, null=True, blank=True)
Courses = models.ForeignKey(Course, related_name='+', on_delete=models.CASCADE, null=True, blank=True)
Section = models.ForeignKey(Section, related_name='+', on_delete=models.CASCADE, null=True, blank=True)
Payment_Type = models.ForeignKey(PaymentType, related_name='+', on_delete=models.CASCADE, null=True)
Education_Levels = models.ForeignKey(EducationLevel, related_name='+', on_delete=models.CASCADE, blank=True,
                                     null=True)
Remarks = models.TextField(max_length=500, null=True, blank=True)

class SubjectSectionTeacher(models.Model):
School_Year = models.ForeignKey(SchoolYear, related_name='+', on_delete=models.CASCADE, null=True)
Education_Levels = models.ForeignKey(EducationLevel, related_name='+', on_delete=models.CASCADE, blank=True)
Courses = models.ForeignKey(Course, related_name='+', on_delete=models.CASCADE, null=True, blank=True)
Sections = models.ForeignKey(Section, related_name='+', on_delete=models.CASCADE, null=True)
Subjects = models.ForeignKey(Subject, related_name='+', on_delete=models.CASCADE, null=True)
Employee_Users = models.ForeignKey(EmployeeUser, related_name='+', on_delete=models.CASCADE, null=True)

class StudentsEnrolledSubject(models.Model):
Students_Enrollment_Records = models.ForeignKey(StudentsEnrollmentRecord, related_name='+',
                                                on_delete=models.CASCADE, null=True)
Subject_Section_Teacher = models.ForeignKey(SubjectSectionTeacher, related_name='+', on_delete=models.CASCADE,
                                            null=True)

Я кодирую это в моей модели

def studentenrolled(sender,instance, **kwargs):
    if kwargs['created']:
        ireceived = StudentsEnrolledSubject.objects.create(Students_Enrollment_Records=instance.Student_Users,
                                                           Subject_Section_Teacher=SubjectSectionTeacher.Employee_Users)
post_save.connect(studentenrolled, sender=StudentsEnrollmentRecord)

это ошибка, которую я получил

Я просто хочу, чтобы каждый раз, когда администратор вводил / обновлял StudentsEnrollmentRecord.Section и StudentsEnrollmentRecord.Course, он автоматически выполнял поиск Employee_Users из SubjectSectionTeacher и автоматически сохранял в StudentsEnrolledSubject

Я не знаю, правильно ли я поступаюсигнал джанго, пожалуйста, помогите мне!