500 Error on correct username and password.

[swarnava112]

Everytime I am trying to generate accessToken using oauth/token I am getting this error
500 Internal Server Error Internal Server Error The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.
On checking pycharm console I see the following :-
redis.exceptions.DataError: Invalid input of type: 'ObjectId'. Convert to a byte, string or number first.