Bug when trying to authenticate

[AntonioJCosta]

Hello. First of all, thank you for this excellent python package solution.

Description of the problem:

I am trying to authenticate using this code

from O365 import Account, FileSystemTokenBackend


def get_account_access(
    app_id: str,
    app_secret: str,
    token_path: str,
    token_filename: str,
    tenant_id=None,
):

    credentials = [app_id, app_secret]
    if tenant_id is not None:
        credentials.append(tenant_id)

    token_backend = FileSystemTokenBackend(token_path, token_filename)
    account = Account(tuple(credentials), token_backend=token_backend)
    if not account.is_authenticated:
        try:
            account.authenticate(scopes=["basic", "message_all"])
            return account
        except Exception as e:
            raise Exception(f"Authentication failed: {e}")
    return account

But when I run this I get this error: 

Traceback (most recent call last):
  File "main.py", line 25, in <module>
    account = get_account_access(APP_ID, APP_SECRET, TOKEN_PATH, TOKEN_FILENAME)
  File "/root/tools/AutomacaoAbuse/get_account_access.py", line 21, in get_account_access
    if not account.is_authenticated:
  File "/usr/local/lib/python3.6/site-packages/O365/account.py", line 69, in is_authenticated
    token = self.con.token_backend.get_token()
  File "/usr/local/lib/python3.6/site-packages/O365/utils/token.py", line 94, in get_token
    self.token = self.load_token()  # store the token in the 'token' property
  File "/usr/local/lib/python3.6/site-packages/O365/utils/token.py", line 187, in load_token
    token = self.token_constructor(self.serializer.load(token_file))
  File "/usr/lib64/python3.6/json/__init__.py", line 299, in load
    parse_constant=parse_constant, object_pairs_hook=object_pairs_hook, **kw)
  File "/usr/lib64/python3.6/json/__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "/usr/lib64/python3.6/json/decoder.py", line 342, in decode
    raise JSONDecodeError("Extra data", s, end)
json.decoder.JSONDecodeError: Extra data: line 13 column 2 (char 1922)

I am running this code on my personal machine and it's working fine, with the same python version and package version.

Package version that I am using: 2.0.19 Python version: 3.6.8

May you help me with this issue? Thank you for your attention.

[alejcas]

It seems that the token file stored is malformed. Try to delete it, authenticate again and don't touch the file manually. It should work without issues.

[AntonioJCosta]

Even when the backend token is empty I am getting this error.

[alejcas]

Token backend is always FileSystemTokenBackend by default

[Lakehurst-RHUL]

I was also getting this issue, but have resolved by deleting the token.

Is there anyway to ensure this does not happen again? Thank you