After recently changing your password and logging back in to your Mac, you might see an alert that the system was unable to unlock your keychain.
This is expected after a password change, because the passwords for your Xavier account and Mac Keychain no longer match.
To resolve this issue, try these steps:
If you see other messages asking for your old password, reset your keychain manually:
Open Keychain Access, which is in the Utilities folder of your Applications folder.
Choose Preferences from the Keychain Access menu, then click the Reset My Default Keychain button in the preferences window.
After you enter your new password, Keychain Access creates an empty login keychain with no password. Click OK to confirm.