Enter password for default keyring to unlock
This occurs because the keyring has been locked with the old OS password.
The solution ?
- Choose Applications -> Accessories -> Passwords and Encryption Keys ( or simply run the command seahorse )
- Navigate to the Passwords tab
- Select the Passwords: login link
- Click the right mouse button
- Choose Change Password
- Enter the OLD OS password
- Enter the NEW OS password - twice
- Click the Change button
- Close the Passwords and Encryption Keys applet