Unable to Use WD External Drive with M3 MacBook

As HWTech indicated, I'll bet the problem is the WD maintenance software that came with the disk. These apps almost always cause problems and should not be used. I recommend that you use Disk Utility to erase and reformat the disk and then reset Time Machine, if that is what you are using to do your backups.

TeacherTerryL wrote:

I only use WD Unlocker because I thought I had to. I installed nothing else from WD. Reviews on Amazon for the WD My Passport indicate users with newer laptops running Sonoma cannot use the drive at all.

If the WD drive has hardware encryption, then you do need to use the WD software to handle the enabling & disabling of the drive's hardware encryption feature (plus unlocking the drive). If you are using the drive's hardware encryption feature, then you will need to use the WD software to unlock and disable the hardware encryption before you can use the drive without the WD software. A Windows PC with the WD software can be used to disable the hardware encryption. If you have an older Mac that is compatible with the WD software, then maybe that can be used as well.

TeacherTerryL wrote:

I only use WD Unlocker because I thought I had to. I installed nothing else from WD.

when you use software from just about any manufacturer for their storage device you run the risk of that same software not being compatible with macOS updates / upgrades. it can cause the software to stop working. at best this will cause you a headache. at worst it can render your data inaccessible. it is always best to use disk utility to erase and format a drive before use to remove any preloaded software.

please see Erase and reformat a storage device in Disk Utility on Mac - Apple Support

Reviews on Amazon for the WD My Passport indicate users with newer laptops running Sonoma cannot use the drive at all.

if the drive had the WD software installed before sonoma came out, it is no surprise that software is not compatible with sonoma.

EDITED

TeacherTerryL wrote:

I can't erase and format the WD drive because I can't unlock it. The error message says Unlocker Quit Unexpectedly.

well since you are using such software, i think your options are somewhat limited. 

you may want to contact WD and see if there is an update for their software.

alternatively, if you have a backup you can revert your macOS to the version of macOS that the drive was working on and transfer your data to another storage device and then erase and format the WD device before putting it back into service.

and if you decide go the "new drive" route, please avoid any drive that is supposedly "Mac ready" and instead erase and format a drive before use.

If you are using the proprietary WD software to manage this external drive, then you will need to contact WD support for assistance. It is up to WD to make sure their software is compatible with macOS, not the other way around.

Or perhaps the external SSD has failed.