Unkown celery version after google auth redirect

[BuildWithLal]

When i am trying to login using Google auth, after successfully logged in google and redirect, it throws this error. This works fine on local but not on prod.

I have added the correct origin and redirect urls to google developer console. I am passing correct env vars to flower as well for google auth. This was working before but suddenly stopped working on both Staging and Prod. Local seems fine till now.

It looks like you have found a bug! You can help to improve Flower by opening an issue in https://github.com/mher/flower/issues

Unknown Celery version
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/tornado/web.py", line 1704, in _execute
    result = await result
  File "/usr/local/lib/python3.7/site-packages/tornado/gen.py", line 769, in run
    yielded = self.gen.throw(*exc_info)  # type: ignore
  File "/usr/local/lib/python3.7/site-packages/flower/views/auth.py", line 26, in get
    code=self.get_argument('code'),
  File "/usr/local/lib/python3.7/site-packages/tornado/gen.py", line 762, in run
    value = future.result()
  File "/usr/local/lib/python3.7/site-packages/tornado/auth.py", line 919, in get_authenticated_user
    body=body,
tornado.httpclient.HTTPClientError: HTTP 400: Bad Request

This is how i run flower. Flower is running in a container.

flower -A proj --address=0.0.0.0 --port=5050 --db=./flower.db --persistent=true --debug=true --auth=.*@example\.com$ --auto-refresh=false

celery==4.4.7
flower==0.9.7
tornado==6.1