Status 400: Additional permissions are required.

During authentication, you receive this error message:

Status 400: Additional permissions are required.  Please ensure you select all permission checkboxes and try again.

Causes

• The required scopes were not selected or enabled during the authentication process
• (Google account) The user hit 'Cancel' instead of 'Allow' during the Google permissions page 

Resolution

• As a test, try re-authenticating with all scopes.  If this passes but the user doesn't want all scopes enabled, re-authenticate again with only the required scopes.
• Ask the user to re-authenticate, and select 'Allow' during the Google permissions page

Resources:

Authentication Scopes