GAE production + Django + Gunicorn Error: HaltServer 'Worker failed to boot.' 3

I run my Django project on localhost by 'python manage.py runserver' - it works. I deploy it on Google App Engine - on xxx.appspot.com it print 502 Bad Gateway/by Ngnix and raise followed:

gunicorn.errors.HaltServer:

    Traceback (most recent call last):
  File "/env/bin/gunicorn", line 10, in <module>
    sys.exit(run())
  File "/env/lib/python3.7/site-packages/gunicorn/app/wsgiapp.py", line 58, in run
    WSGIApplication("%(prog)s [OPTIONS] [APP_MODULE]").run()
  File "/env/lib/python3.7/site-packages/gunicorn/app/base.py", line 228, in run
    super().run()
  File "/env/lib/python3.7/site-packages/gunicorn/app/base.py", line 72, in run
    Arbiter(self).run()
  File "/env/lib/python3.7/site-packages/gunicorn/arbiter.py", line 229, in run
    self.halt(reason=inst.reason, exit_status=inst.exit_status)
  File "/env/lib/python3.7/site-packages/gunicorn/arbiter.py", line 342, in halt
    self.stop()
  File "/env/lib/python3.7/site-packages/gunicorn/arbiter.py", line 380, in stop
    and not self.cfg.reuse_port
  File "/env/lib/python3.7/site-packages/gunicorn/config.py", line 201, in reuse_port
    @property
  File "/env/lib/python3.7/site-packages/gunicorn/arbiter.py", line 242, in handle_chld
    self.reap_workers()
  File "/env/lib/python3.7/site-packages/gunicorn/arbiter.py", line 525, in reap_workers
    raise HaltServer(reason, self.WORKER_BOOT_ERROR)
gunicorn.errors.HaltServer: <HaltServer 'Worker failed to boot.' 3>

Python 37 Django 2.1.14

I`m first time with Django&GAE, pleese help