Python personal gateway credentials, A problem occurred while processing your Python script.

I was trying to refresh of power bi report, but got an error concerning invalid credentials
(Your data source can't be refreshed because the credentials are invalid. Please update your credentials and try again.).
The power bi report can run normally on BI. The other data sources connect fine through the personal gateway. When I click on 'Edit Credentials' for Python, I get the following specifics:
Failed to update data source credentials: ADO.NET: A problem occurred while processing your Python script. Here are the technical details: Access is denied.

Please give me some support!!!!