Error running developmental server in Django project some issue with migration

I have developed a project for SASS with django tenate. While migratiing, I got the following error

it seems, like it is related to migration file.

(acc_venv) D:\\workik_projects\\AccrediDoc_v2\>py manage.py makemigrations report
  
Traceback (most recent call last):
  
  File "D:\\workik_projects\\AccrediDoc_v2\\manage.py", line 22, in \<module\>
  
    main()
  
  File "D:\\workik_projects\\AccrediDoc_v2\\manage.py", line 19, in main
  
    execute_from_command_line(sys.argv)
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\management\\\__init_\_.py", line 442, in execute_from_command_line
  
    utility.execute()
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\management\\\__init_\_.py", line 436, in execute
  
    self.fetch_command(subcommand).run_from_argv(self.argv)
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\management\\base.py", line 416, in run_from_argv
  
    self.execute(\*args, \*\*cmd_options)
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\management\\base.py", line 457, in execute
  
    self.check(\*\*check_kwargs)
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\management\\base.py", line 492, in check
  
    all_issues = checks.run_checks(
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\core\\checks\\registry.py", line 89, in run_checks
  
    new_errors = check(app_configs=app_configs, databases=databases)
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\contrib\\auth\\checks.py", line 101, in check_user_model
  
    if isinstance(cls().is_anonymous, MethodType):
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\db\\models\\base.py", line 537, in \__init_\_
  
    val = field.get_default()
  
  File "D:\\workik_projects\\AccrediDoc_v2\\acc_venv\\lib\\site-packages\\django\\db\\models\\fields\\related.py", line 1176, in get_default
  
    if isinstance(field_default, self.remote_field.model):
  
TypeError: isinstance() arg 2 must be a type, a tuple of types, or a union

Check the fields you define, looks like you assign an object to default anywhere

Well, Django’s system check instantiates your custom user model during makemigrations. One of its ForeignKey fields has a default that returns a model class or unresolved lazy reference, so when Django evaluates the default it runs isinstance(default, remote_field.model). Because the relation still points to the string 'app.Model', remote_field.model isn’t a class yet and isinstance() raises the TypeError.

ForeignKey defaults must return a resolved model instance or its PK after the app registry is ready; returning the model class (or resolving too early) breaks Django’s checks.

Check this code out and let me know if it works

from django.apps import apps
from django.core.exceptions import ObjectDoesNotExist

def default_tenant_id():
    Tenant = apps.get_model('tenants', 'Client')
    try:
        return Tenant.objects.get(schema_name='public').pk
    except ObjectDoesNotExist:
        raise ValidationError("Default tenant not configured")

class User(AbstractUser):
    tenant = models.ForeignKey(
        'tenants.Client',
        on_delete=models.CASCADE,
        default=default_tenant_id,
    )
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