Mac OS X 10.5.3 or later: Time Machine – "Backup volume could not be mounted" after changing network volume’s password

If you use Time Machine with a network backup volume (such as a Time Capsule disk or an AFP share from another computer) in Mac OS X 10.5.3 or later, "Backup volume could not be mounted" may appear in Time Machine preferences and back up attempts may not work. This may happen if the password for the network backup volume has changed since Time Machine was originally configured.