Following a recent password change, a user can log on successfully to an Apple computer but cannot access a web-based service. An error message displays each time the user attempts to authenticate…

passwd is a Unix command for changing a local macOS user account password; it has no function related to web service credentials or stored third-party authentication tokens.

FileVault is macOS full-disk encryption and controls access to data on the drive at rest; it plays no role in web-based authentication or credential storage for external services.

macOS Keychain Access stores saved usernames and passwords for websites, applications, and network services, and automatically supplies them during authentication. When the user changed their web service password, the old password remained in Keychain and is being auto-submitted, causing the authentication error. Locating and deleting or updating that Keychain entry will resolve the issue without affecting the local account login.

Gatekeeper enforces application security policies by verifying developer signatures and source of apps before they run; it does not manage user passwords or web service login credentials.