Traceback (most recent call last):
  File "/openedx/venv/lib/python3.8/site-packages/django/core/handlers/exception.py", line 34, in inner
    response = get_response(request)
  File "/openedx/venv/lib/python3.8/site-packages/django/core/handlers/base.py", line 115, in _get_response
    response = self.process_exception_by_middleware(e, request)
  File "/openedx/venv/lib/python3.8/site-packages/django/core/handlers/base.py", line 113, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "/opt/pyenv/versions/3.8.6/lib/python3.8/contextlib.py", line 75, in inner
    return func(*args, **kwds)
  File "/openedx/venv/lib/python3.8/site-packages/django/views/decorators/csrf.py", line 54, in wrapped_view
    return view_func(*args, **kwargs)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/viewsets.py", line 125, in view
    return self.dispatch(request, *args, **kwargs)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/views.py", line 509, in dispatch
    response = self.handle_exception(exc)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/views.py", line 469, in handle_exception
    self.raise_uncaught_exception(exc)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/views.py", line 480, in raise_uncaught_exception
    raise exc
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/views.py", line 506, in dispatch
    response = handler(request, *args, **kwargs)
  File "/openedx/venv/lib/python3.8/site-packages/edx_rbac/decorators.py", line 41, in wrapped_view
    return view(self, request, *args, **kwargs)
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/api/v1/views.py", line 213, in course_enrollments
    if serializer.is_valid():
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/serializers.py", line 725, in is_valid
    self._validated_data = self.run_validation(self.initial_data)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/serializers.py", line 607, in run_validation
    value = self.to_internal_value(data)
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/api/v1/serializers.py", line 709, in to_internal_value
    validated = self.child.run_validation(item)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/serializers.py", line 419, in run_validation
    value = self.to_internal_value(data)
  File "/openedx/venv/lib/python3.8/site-packages/rest_framework/serializers.py", line 478, in to_internal_value
    validated_value = validate_method(validated_value)
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/api/v1/serializers.py", line 962, in validate_course_run_id
    if not enterprise_customer.catalog_contains_course(value):
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/models.py", line 594, in catalog_contains_course
    if EnterpriseCatalogApiClient().enterprise_contains_content_items(self.uuid, [course_run_id]):
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/api_client/lms.py", line 103, in inner
    self.connect()
  File "/openedx/venv/lib/python3.8/site-packages/enterprise/api_client/lms.py", line 80, in connect
    jwt = JwtBuilder.create_jwt_for_user(self.user)
  File "/openedx/edx-platform/openedx/core/djangoapps/oauth_dispatch/jwt.py", line 36, in create_jwt_for_user
    return _create_jwt(
  File "/openedx/edx-platform/openedx/core/djangoapps/oauth_dispatch/jwt.py", line 120, in _create_jwt
    'preferred_username': user.username,
AttributeError: 'NoneType' object has no attribute 'username'
2021-09-22 13:38:32,868 ERROR 113 [django.request] [user None] [ip None] log.py:222 - Internal Server Error: /enterprise/api/v1/enterprise-customer/35d98c64-842a-49a7-a1f4-8e5d090b57f5/course_enrollments/