Tahoe not recognizing External Hard Drives that still work fine on Sequoia

Update, I’d installed my security software before checking external hard drives, then I noticed I couldn’t access them, then I came across a post explaining it, my security software Eset, blocks access to installed external HDD’s by default, found how to switch that off and they’ve been fine since, I suspect that most similar software does this ?

davidjames1701 wrote:

I'm really feeling this is Apples problem with Tahoe ?

I have no problems mounting external drives with Tahoe, I routinely use 7 SSDs (and an NAS). See if the problem is present when you boot in safe mode, which disables 3rd party extensions and performs some system cleanup.

Start up your Mac in safe mode - Apple Support

This user (earlier in this thread) reported that drives mount in Safe Mode:

tpawluk wrote:

The drive works in safe mode. It mounts correctly. I have also tried First Aid and Erase in Safe mode. Both successful. But as soon as I start normal mode, the problem persists. :(

That puts the problem squarely on 3rd party software. Other users have traced the issue to 3rd party encryption utilities like the ones that often come preinstalled on new external drives (Samsung and LaCie/Seagate do this, for example), those apps may not be compatible with Tahoe. Personally, when I get a new external drive the first thing I do is erase it with Disk Utility, then set it up as desired (GUID/APFS, and with encryption if I want it on that drive).

You could try this:

Potential Issues and Solutions 

• Drive Not Mounting: Some users have reported that Tahoe doesn't recognize external drives.
  • Check System Settings: Go to Apple menu > System Settings > Privacy & Security and ensure "Allow Accessories to Connect" is set to "Automatically when unlocked".
  • Reboot: Sometimes, a background process after a failed mount attempt can eventually allow the drive to mount; check the Terminal for a fsck process.

Thanks for putting me in the right direction. Did notice the extra connected devices option in ESET when it first appeared, but did not link it directly to my USB drives. They did connect but not mount, without any warning from ESET.

Thanks, that turns out to be a problem with my MacBook Pro 2019 - I lost 1 day trying to figure out what was wrong, and yes - it was Eset.

Restart in Safe Mode and test. If OK then restart normally and retest. I have several drives and no issue.

Barney-15E wrote:

NateKyngPresents wrote:

This is an Apple Forum, is it not? What a nonsensically rude response.

It is hosted by Apple, but nobody that actually works for Apple in a capacity that can affect macOS in any way monitors this Forum. If you want Apple to know about your dreams and desires, you need to actually contact Apple via their Feedback site, Feedback app, or call them via the Support website.

FYI, this thread is lost. I count at least six different external drive related issues here.

1. Issue with third party software.....the OP @tpawluck
2. Seagate proprietary software issue....@Psych13
3. File system corruption.....@syops
4. Hardware or compatibility issue with a dock.....@jaylynn0528
5. System Settings issue....@JameOgilviePhoto
6. Unknown--not enough details.....@davidjames1701 & @workshopbear

Each "Me too" user should start their own thread to get the attention their problem deserves. There is no way to help each person when their exact issue has a completely different source.

People also need to be aware that not every problem with their computer setup is due to Apple breaking things....four of these six issues are not Apple's fault (#'s 1-4, 5 is debatable). Upgrading to a new major version of an OS will always cause some third party app or devices to break...it is inevitable and it is up to those third parties to make their product work with the new OS usually by providing a software update for their third party software. Also, if a user has any existing issues with their computer, then a major OS upgrade will still have those issues plus possibly some new ones due to compatibility issues (again with third party apps & hardware).

I'm having the same problem on my Macbook Air. Connected my Seagate external drive just now where I store my Photos library and got the message that a driver needs to be installed....it told me to disconnect my drive and restart my laptop-which I did....but I then just got the same prompts and was asked to do the same thing. Most frustrating. And yes, I, too, upgraded to Tahoe 26.0.1 just today.

See screenshots below. Interestingly, when I connect my Kingston Ironkey Vault Privacy 50 USB, I don't have any issues. It's my Seagate drive that has issues.

[Edited by Moderator]

Bugs can be reported to Apple here:

Feedback - macOS - Apple

are you running any security software ?

It’s very annoying. Try using a usb interface between your device and the Mac. It worked for me.

Hi, glad I've found this, I've exactly the same problem on my iMac i7, worked fine before, but after I upgraded to Tahoe, no external drives are recognised, show up in disk utility ok, and I can re format them, but will not mount at all, when I click "Mount" nothing at all happens, but if I plug the same drive into my 2013 MacBook Pro, it recognises them instantly, I'm really feeling this is Apples problem with Tahoe ?

I've checked my Allow Accessories, and I've also rebooted my Macbook Air, and still no luck, with Tahoe 26.0.1.

I tried using a usb interface and then it worked easily. Very strange issue. Just something to remember maybe, for next time.

I restarted it in safe mode and it still did not recognize my external drive. What is the next step in trouble-shooting? Apparently, it recognizes my external drive when it is directly connected to my laptop but not to my USB dock which is how I upload my images. I am quite perplexed now.