Version 4.3.3 AttributeError: 'NoneType' object has no attribute 'split'

[kosuke-zhang]

 File "/var/lang/python37/lib/python3.7/threading.py", line 926, in _bootstrap_inner

    self.run()

  File "/var/lang/python37/lib/python3.7/threading.py", line 870, in run

    self._target(*self._args, **self._kwargs)

  File "/var/user/django/utils/autoreload.py", line 64, in wrapper

    fn(*args, **kwargs)

  File "/var/user/django/core/management/commands/runserver.py", line 118, in inner_run

    self.check(display_num_errors=True)

  File "/var/user/django/core/management/base.py", line 423, in check

    databases=databases,

  File "/var/user/django/core/checks/registry.py", line 76, in run_checks

    new_errors = check(app_configs=app_configs, databases=databases)

  File "/var/user/django/core/checks/caches.py", line 63, in check_file_based_cache_is_absolute

    cache = caches[alias]

  File "/var/user/django/utils/connection.py", line 62, in __getitem__

    conn = self.create_connection(alias)

  File "/var/user/django/core/cache/__init__.py", line 44, in create_connection

    return backend_cls(location, params)

  File "/var/user/django_redis/cache.py", line 53, in __init__

    self._client_cls = import_string(self._client_cls)

  File "/var/user/django/utils/module_loading.py", line 17, in import_string

    module = import_module(module_path)

  File "/var/lang/python37/lib/python3.7/importlib/__init__.py", line 127, in import_module

    return _bootstrap._gcd_import(name[level:], package, level)

  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import

  File "<frozen importlib._bootstrap>", line 983, in _find_and_load

  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked

  File "<frozen importlib._bootstrap_external>", line 728, in exec_module

  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed

  File "/var/user/django_redis/client/__init__.py", line 1, in <module>

    from .default import DefaultClient

  File "/var/user/django_redis/client/default.py", line 12, in <module>

    from redis import Redis

  File "/var/user/redis/__init__.py", line 54, in <module>

    VERSION = tuple(map(int_or_str, __version__.split(".")))

AttributeError: 'NoneType' object has no attribute 'split'