Unable to complete backup. An error occurred while creating the backup folder.

Well, the problem came back again yesterday. I poked around the WD support forums and found this post:

https://community.wd.com/t/backup-fails-on-time-machine/187675

tl;dr: Several people seeing this exact problem with various WD drives and Time Machine, in a variety of configurations. A user claims to have tracked this down to the WD driver / helper utility not being compatible with Sierra and High Sierra. Removing this driver fixed the problem for more than one user.

• Run the Uninstall utility in Applications
• Remove /Library/LaunchDaemons/com.wdc.WDPrivilegedHelper.plist
• In System Preferences > Users and Groups > Login Items, remove WDDriveUtilityHelper

I've tried this just now and restarted my laptop. Will try to remember to report back in a few days if it fixed the problem!

I suggest that you try to narrow down the possibilities to try to isolate the real cause of the problem.

If you want to try this.......disable Time Machine Editor. It used to be that you had to uninstall the application to fully disable it, but I'm not sure about the current or more recent versions. I do notice that there was an update in July, which may or may not be a factor here as well.

If you are running High Sierra (10.13.x) on your Mac.....that may be a factor as well.....because of increased security.

Once Time Machine Editor is disabled, go ahead and let Time Machine operate normally for a day or two. Do things operate normally that way?

If they do, then try enabling Time Machine Editor again. If things are still messing up.....you know that you have a Time Machine Editor issue with the TME software. Best to post on the Time Machine Editor support forum in that case.

I'm having this same error message, also with a WD external drive connected to my 2018 MacBook Pro via a CalDigit Thunderbolt 3 hub, MacOS 10.13.6. First 5 backups went fine, then got the error message about not being able to create a backup folder. After that, I was not able to manually start the backup either. I am not using Time Machine Editor, though - just letting backups occur at the default interval. I just ejected and remounted the drive, and now Time Machine is running. Hope I don't need to do this every day! Any suggestions welcome!

If I eject the backup disk, unplug it and plug it back in, then I can back up without this error.

I just ejected and remounted the drive, and now Time Machine is running. Hope I don't need to do this every day! Any suggestions welcome!

It sounds like you both have the same or at least similar issue.

theofani.. is your USB drive plugged directly into your Mac or is it in a hub of some sort?

What happens is the drive spins down and does not get a spin up again.

When you eject the drive and plug it back in the drive goes through its start up sequence and will become active again.

Some drives seem prone to this.. WD passport does seem to be one of those.

Put your hand on the drive and feel if it is spinning.. or some drives you can hear them.. very softly when they are spinning.

Thanks for the reminder.. actually the problem of the WD utility is of long standing..

Pondini mentions it in his KB from Lion install.. about 8 years ago.

http://www.baligu.com/pondini/TM/C17.html

Do not install the utility.. it is totally unnecessary on a Mac.

Interesting that it's been since Lion :-(

When I initially plugged in the WD drive, I couldn't mount it, erase it using Disk Utility or set it as a Time Machine backup, though the drive showed up in on the USB chain in system information and was visible in Disk Utility. So I installed the WD utility and used it to check the drive was ok and to erase it and format it as HFS-J. Once I did that, I could mount the drive and use it for Time Machine. So I did need the WD utility initially to get going, though it appears it messes things up in the long run. After deleting WD utility, I no longer get the Time Machine errors.

I have this problem using a 256 gb SD card in mac mini [OS10.13.6) NOT FOUND A SOLUTION YET.