Time Machine backup could fail for a variety of reasons, including an issue with the USB connectivity, insufficient storage space on the external hard drive, or a roadblock that prevents the data transfer during backup. But by far, the biggest cause of the ‘Unable to Complete Backup’ error is the WD Utilities program that tries to use the same dependencies as the Time Machines creating a conflict. If you’re currently troubleshooting the same issue, there are 3 main troubleshooting methods that you should follow:
1. Uninstall the WD Utilities program
WD Utilities is capable of doing some of the same functions that are available with Time Machine. Because of the way macOS is built, this 3rd party program has to use some of the same dependencies as the built-in backup app. This creates a conflict in certain scenarios (especially when WD is also performing a task in the background). If you have WD Utilities installed and you are attempting to create a backup on a WD external drive when you get the ‘Unable to Complete Backup’ error, uninstalling the program and eliminating every file remnant should help you fix the issue. IMPORTANT: It’s very important to go through all the trouble of accessing the Demons folder and removing the com.WDPrivilegedHelper.plist file from the underlying folder. If you skip this step, the conflict will NOT be resolved. Here’s a quick guide on uninstalling the WD Utilities program from Mac and removing any underlying dependency manually:
2. Close Backup Process & Hard Restart
Another thing that you need to do if Time Machine fails to recognize your backup disk or remains stuck every time you retry this procedure is to hard restart your Mac. This might seem like a simple trick, but refreshing the local cache is one of the best ways to fix backup errors thrown by Time Machine. Note: It’s important to ensure that you uncheck the ‘Reopen windows when logging back in’ option when initiating a restart. If you keep this option, some of the local cache accumulation will be maintained which defeats the purpose of this method. Here’s a quick guide that will show you how to ensure that the Time Machine backup process is not running in the background and initiate a hard restart:
3. Clean the Time Machine Cache files manually
Normally when you hard restart your macOS, the time machine cache gets cleared automatically. But there are situations where an unfinished backup will prevent this from happening. If you see the ‘Unable to Complete Backup’ error occurring as the backup fails to finish, cleaning the Time Machine cache files manually will most likely fix this issue. Note: Time Machine enables you to recover data from local copies of your Mac’s files, even if your Time Machine backup disc is unavailable when an external drive is connected. By clearing the cache data used by Time Machine, you will most likely remove the stuck backup from the Time Machine queue so you can start a new backup that won’t end with the ‘Unable to Complete Backup’ error. But in order to do this, you’ll first need to connect your external drive and disable the ‘Back up automatically option’ under System Preferences > Time Machine. After you do this, you can safely delete the backup cache file (Backups.backupdb) on the external drive. Here’s a quick guide on how to do this:
