
If you don't know the TM name, go to Time Machine Prefernces and check out.Step 2: Type: $ chflags -R nouchg '/Volumes/.sparsebundle' and hit Return.Step 1: Open Terminal on Mac and type: $ sudo su - and hit Return. Notice: Before starting the process, You should stop Time Machine: Time Machine Preferences > Toggle Time Machine 'OFF'.

Reformatting a disk erases all data stored on the disk, so you might want to move important files to another disk first.If you select a differently formatted drive for use with Time Machine, your Mac automatically prompts you to erase it for Time Machine. Time Machine requires that an external drive be formatted like a Mac startup disk: Mac OS Extended (Journaled) with a GUID Partition Table (GPT). If you're backing up to an external drive, check the formatting of the drive.If you're backing up to an external third-party drive, check with the drive manufacturer to make sure the drive's firmware is up to date.If you're using a USB hub or a similar device, try connecting the drive directly to your Mac or base station.If you're using a drive connected to a port on your Mac or AirPort Extreme Base Station, make sure that the drive is turned on.If Time Machine finds an issue with your backup, it displays a message with details.While holding down the Option key on your keyboard, click the Time Machine menu in the menu bar, then choose Verify Backups.If you back up to a server, AirPort Time Capsule, or drive connected to your AirPort Extreme Base Station, make sure that your current Time Machine backup doesn't have any issues that could prevent further backups: To restart, unplug the base station from AC power for 5 seconds, then plug it back in. Restart your base station and see if the issue continues.If you're using an AirPort Time Capsule or a drive connected to an AirPort Extreme Base Station, make sure that your AirPort firmware is up to date.Restart your Mac and see if the issue continues.

