Unable to access External Drives and Disk Utility after updating to macOS Sonoma.

Sonoma 14.4.1 did NOT fix the issue. None of my external drives are visible after the update.

Unbelievable...

I have been having this issue with my two Western Digital external HDDs (exFAT formatted) since I upgraded my MacBook Air M1 to Sonoma, but I could find two workarounds and one fix (not ideal, but seems to be working). As this laptop suffers from scarce USB-C ports, I have been connecting these drives via a Baseus 6-in-One USB hub.

I recommend you who still can't access your external drives to try one of these and see how they work for you.

It seems that MacOS actually had unknown issues mounting the drives. The system does acknowledge there's a drive inserted in one of its USB ports, but isn't mounting the drives immediately as it should.

Workaround #1: case you have a Windows machine laying around, plug your device to it. Windows will give an alert saying 'the unity is damaged. Do you want to repair it?'. Accept the scan. It can take some time, depending on your drive size. My 2TB unit takes around 10 minutes. My 5TB one takes around 30. Can be still faster than workaround #2, depending on your drive size

Workaround #2: for whatever the reason, as soon as MacOS gives up mounting the drive, it begins a scanning proccess running in the background (which you can watch by typing 'ps aux | grep fsck' at the Terminal). My Terminal gives me two lines as the answer, and one of them ends with '/dev/rdisk4s1' (rdisk4s1 is probably the drive id, yours can be different) - that line contains the exact time count of that scanning proccess.

When this background scan finishes, the drive will mount. It might take a lot of time. My 5TB drive takes almost one hour until it mounts. But in the end it will and you can use your drive as usual.

Both these workarounds aren't practical if you work with your Mac. But feel free to try. If they worked for me, chances are they'll work for you too.

Now, the fix. This one did it for me for good:

• Apple Icon > System Settings. At 'Privacy & Security' tab, look for 'Allow Accessories to Connect'. Set it to 'Automatically when unlocked'. Try connecting the drive again. Should work.

Good luck!

And please, Apple, solve this next update! This is just too frustrating.

yes it not working with my WD black either....Apple are you going to sort this or what?

Update: I found a fix that worked for me on another thread. Someone talked to an apple engineer who suggested using a USB to USB-C adapter. I was highly skeptical but having tried everything and having some adaptors on hand I gave it a try and it worked!

so on a M3Pro I plugged in a USB-C to USB adapter and then plugged a USB to USB-C adapter into the first adapter and then my SSD into the second adapter and it now mounts.

Ridiculous 😂 have no idea why this would work but hey at least it’s working.

Apple needs to prioritize a proper fix to this as this is unacceptable to have a such a serious bug be going on for 6 months now.

Having the same issues, so every time I connect my outboard drive, I go to System Preferences, then Siri and Spotlight, then to the bottom where "Spotlight Privacy" is tabbed.

Click on Spotlight Privacy, drag your drive in, then hit the "-" sign and it will be recognized and become searchable for that session until you eject it. Not the most elegant solution for a new operating system, @Apple. WTAF? Fix this. Or is it just another attempt to make you spend more money on memory?

Hope (everything but the screed) helps.

I think it is grossly irresponsible of Apple to allow the Sonoma mess to continue...

Apple has done nothing to correct this from what i read daily...

So many users wasting time with an OS that Should Have Been Fully Functional BEFORE it was released to the masses...

But Apple didnt do their due diligence and subsequently released an abysmal mess of an OS..

How many of us are still willing to tolerate this?

I know i am not...

It is Not our place as users to troubleshoot the buggy OS.

And we surely are not being compensated by Apple for all the lost time and in some cases lost Data all due to some coding that they seem to have no clue as to how to fix it.

shameful...

wonder if this will get pulled down as it is not singing praises, rather stating Facts.

To be honest, I don't think Apple are interested..........They have to be aware of the issue and are choosing to do nothing. time to swap back to Windows

Somona is a disgrace. The problem should have been sorted long time ago. Brand new Lacie ssd 4tb takes forever to write Final Cut files. It is not possible to format into any APFS. Giving different 698-- reports.

Apple - be professional and sort it! Look at all the complaints all over the internet!

I recently updated my 2023 Mac mini to Sonoma 14.2.1 from the original OS, Ventura 13.6. My external 2T SSD drive formatted in APFS worked without flaw until I installed Sonoma. My external drive disappeared. I tried multiple recommended fixes to restore access to this drive. All my documents and even my Time Machine are on this external drive! So I went back to Ventura 13.6.3. Pain in the *ss, but it worked. Thankfully, TM backed up a few hours before installing Sonoma, and none of the files on the external drive were corrupted! Reading the complaints in this thread, it seems beyond the pale for Apple to release an OS that does this to 3rd party external drives, drives that were in perfect working order on older versions of the OS. And then offer up as support reformatting the drive! What kind of arrogance is this? I'm lucky to have been able to install a clean Ventura OS and then restore everything from Time Machine. I won't touch Sonoma OS again!

Why on earth should anyone who paid good money for superior Apple hardware have to go through all this, just to get a external drive that was formerly functioning perfectly to work again with a brand new, shiny, state of the art OS like Sonoma?

Confirm. Apple remove negative comment .

i wrote several times about this problem.

the only solution is wait 30 minutes every time you insert an HD. Or recover it with windows.

MacOS is not for professional use anymore .

give a chance to windows .

I'm not techy so apologies if not relayed properly but this has been my experience. I had a 5TB Lacie drive, after the upgrade to Sonoma, the drive will not mount. Spent 7 hours on the phone with an Apple "engineer". Changed security settings, modified different items on the computer trying to problem solve. Nothing. Then tried my old computers - no longer recognizable. The engineer could not figure it out. Told me I need to reformat my drive to work with Sonoma and try data recovery for my hard drive, probably will come with a cost. I gave up. Bought a new 8TB LaCie drive off the Apple site. (By the way I have the new M3 MacBook Pro. I waited to get the M3 because my iMac and MacBook are both no longer supported even though they worked perfect, they are circa 2013.)

New LaCie 8TB drive works for about two weeks. Then stops being recognized - after of course I had moved all my data to the drive. Spent another full day on the phone with Apple Engineers. No solution. They are escalating to Senior Engineers and will "get back to me". Expect 1-2 weeks. I sent them this thread.

Then I called LaCie. They have agreed to a "complementary" recovery on the 8TB drive I bought less than three weeks ago, but my other drive which is no longer under warranty, the original 5TB Lacie Rugged - they basically told me too bad. The 8TB recovery - likely will take 30 days.

I also have two WD externals and they seem to currently be working fine, but my LaCie d2 Professional (8TB) was also working fine for several weeks before it stopped being recognized.

FYI...M3 you cannot go backwards with the OS. No longer an option. If you can avoid updating to Sonoma - I'd recommend putting it off.

I was told by Seagate / LaCie this also happened with Ventura. Regardless - I'd be VERY careful with any external drives with significant data on a computer running Sonoma until they is resolved. Currently - NOT RESOLVED by Apple or Seagate / LaCie. As of right now, I would NOT connect it to your computer with Sonoma until this is fixed.

Small Update : I just had it happen with an SD card on a Mac Studio M1 Max (using its built-in reader). The SD card was working and while copying some files, it just disconnected (crashing finder and had to restart). Now the mac won't read that particular card anymore. It works perfectly fine on any other device. Inserting any other SD card in the mac also works fine. Seems like once something gets disconnected, that's it for that media.

Nope, 14.2 still no fix.

I moved to Mac OS when Windows Vista was a disaster.

Now Sonoma and no external drives are working as they should. Usb hub not working .. Apple, after many good years you have actively kicked me out.