Google AYI Vice Kitのエラーについて

Google AYI Vice Kit（V1の方）を２０２０年１月に購入して使用していましたが、
最近起動したところ、エラーで使用できません。
AYI Voice KitはGoogole cloud Platformを使用して、スマートスピーカーとして
使用するものです。　RaspberryPiで動作しています。

エラーは、以下になります。

pi@raspberrypi:~/AIY-projects-python $ src/examples/voice/assistant_grpc_demo.py

DEBUG:google.auth.transport.requests:Making request: POST https://oauth2.googleapis.com/token
DEBUG:urllib3.connectionpool:Starting new HTTPS connection (1): oauth2.googleapis.com:443
DEBUG:urllib3.connectionpool:https://oauth2.googleapis.com:443 "POST /token HTTP/1.1" 400 None
Traceback (most recent call last):
File "src/examples/voice/assistant_grpc_demo.py", line 57, in <module>
main()
File "src/examples/voice/assistant_grpc_demo.py", line 49, in main
language_code=args.language)
File "/opt/aiy/projects-python/src/aiy/assistant/grpc.py", line 205, in init
super().init(language_code, volume_percentage)
File "/opt/aiy/projects-python/src/aiy/assistant/grpc.py", line 64, in init
credentials = auth_helpers.get_assistant_credentials()
File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 132, in get_assistant_credentials
return _try_to_get_credentials(credentials_file)
File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 100, in _try_to_get_credentials
return _load_credentials(_ASSISTANT_CREDENTIALS)
File "/opt/aiy/projects-python/src/aiy/assistant/auth_helpers.py", line 63, in _load_credentials
credentials.refresh(http_request)
File "/usr/local/lib/python3.5/dist-packages/google/oauth2/credentials.py", line 136, in refresh
self._client_secret))
File "/usr/local/lib/python3.5/dist-packages/google/oauth2/_client.py", line 237, in refresh_grant
response_data = _token_endpoint_request(request, token_uri, body)
File "/usr/local/lib/python3.5/dist-packages/google/oauth2/_client.py", line 111, in _token_endpoint_request
_handle_error_response(response_body)
File "/usr/local/lib/python3.5/dist-packages/google/oauth2/_client.py", line 61, in _handle_error_response
error_details, response_body)
google.auth.exceptions.RefreshError: ('invalid_grant: Bad Request', '{\n "error": "invalid_grant",\n "error_description": "Bad Request"\n}')
pi@raspberrypi:~/AIY-projects-python $