My WD Passport for Mac won’t mount on my Mac OS following the latest Catalina update

It does not show in disk utilities at all? Unless you WD drive is full of 32 bit apps that should not matter. If you go to the Apple (About this Mac) system report and then USB. Does the drive show up. Also with the drive connected and starting up with the option key. Do you see the drive. If so, go to recovery and use disk utilities to try and mount or run repair on the drive. Did you install drivers and software for the drive and have you check for any updates for it from the WD site? Did you install WD Discovery for Mac? There is a newer version out. Most cases when using an external drive you do not need drivers or software from the drive manufacture to use it on a Mac.Connect and use other storage devices with Mac - Apple Support

https://support.wdc.com/downloads.aspx?p=294&lang=en

Jokepin wrote:

When I connect the MyPassport Drive the WD Unlocker symbol appears, but not the drive, which used to be the case before the Catalina update. When I click on the WD Unlocker all that does is tell me to "run the WD Drive Unlocker application from the WD Drive Unlocker CD associated with the drive you want to unlock".

I have reinstalled the WD Discovery for Mac, but still the My Passport drive doesn't show up.

the fact that you are using WD's software could be the cause of your issue. 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.

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 catalina 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.

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

File system formats available in Disk Utility on Mac - Apple Support

What formate is the drive? Are you running it thru a hub? If thru a hub run it direct.

https://howtosetup.co/wd-my-passport-not-showing-up-mac/