External hard drive connected to the USB port of an AirPort Extreme Base Station (802.11ac) on your network.
According to Apple's official instructions ( ), when you have a problem with Time Machine, check these things if you see an alert that Time Machine is unable to back up your data, or if you can't select your backup disk in Time Machine preferences. One phenomenon to get Time Machine backup failed is that you can't back up or access an existing Time Machine backup, or restore from an earlier backup won't work. Can't Backup or Restore Your Mac Using Time Machine Full stepsĭownload software to recover missing backups > repair unrecognized. Full stepsĬreate a new backup > restart Time Machine > repair with terminal command. Check Time Machine system requirements > check your Mac.
