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

I have a complex external drive set up with multiple data drives (some with partitions) for storing media. These all back up to a Synology Diskstation with Carbon Copy Cloner software via a Macbook Air. The drives are daisy-chained starting with a USBC to Thunderbolt 1 adapter. Everything was working fine till I 'upgraded' to Tahoe. Since then everything has been going wrong. Drives would either connect then disconnect without ejecting properly (bad news for backing up), or would not connect in the first place. It has not even made a difference connecting individual drives directly to the computer. This is not a problem with anything to do with third parties. The problem is with Tahoe. Everything worked fine before. I have gone to System Settings/Privacy/Accessories and changed tried both 'Always allow' and 'Automatically allow when unlocked' but neither have solved the problem. Apple, you need to sort this out.

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.

Check System Settings:•  Go to Apple menu > System Settings > Privacy & Security and ensure "Allow Accessories to Connect" is set to "Automatically when unlocked".

The author already stated it is a Mac Studio, not a Mac laptop, so that setting will not exist.

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 ?

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).

xbhuang wrote:

... No Apple technician responded here. Sucks!

Apple does not participate here.

This Support Community is a peer-to-peer forum where users help each other.

If you'd like Apple to be directly involved in your troubleshooting, you can make a Genius Bar appointment using this link: Make a Genius Bar reservation - Apple Support

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.

jaylynn0528 wrote:

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.

Is the Dock powered? If it is just using bus power, there likely isn't enough current to support the dock and even one drive connected to it.

syops wrote:

Apple has a real problem. I can't offer a solution but this needs to be shared so Apple can see this is a real bug that must be addressed.

Then you should probably tell Apple.

None of us work for Apple and we also can’t make the “bug” happen.

I tried several drives. An older Seagate drive now works, which didn't before, and my Samsung T7, which contains all my sample instruments, doesn't. I am beyond annoyed. I do hope Apple fixes this soon, I have stuff I need to be getting on with. (safe mode had no effect at all).

tilleron wrote:

I do not even see that as an option on Mac OS 26.1

"Allow Accessories to Connect" is set to "Automatically when unlocked". Does not exist on either of my Macs running 26.1 where are you looking?

Pasting that into Mac Help says Content is Not Available.

What Macs? The setting is present only on laptops, not on desktops.