macOS Tahoe verson 26.0.1 and external hard drive connected with USB

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.

Psych13 wrote:

@owl-53,

Apologies for yet another post but I decided to try and connect an old (and not password protected) Seagate drive to my Macbook Air and it connected just fine. So now I am left wondering whether it was the fact that my other drive was password protected that stopped it from being recognised. The thing is this: prior to me updating to Tahoe OS, I never had an issue with that particular drive, which is why I am left thinking that there is a compatibilty issue with Tahoe and my other drive.

How is it “password protected?” If you are using third-party software to make it password protected, it is very much a certainty the software isn’t compatible with Tahoe.

@TheLastStrawman I forgot to update this thread but installing Toolkit solved the problem for me. It's been a couple of weeks but I screen shotted the instructions from Seagate and am attaching them here for you. This worked for me. They are easy to follow but what Seagate advised me (via a chat session) is to disconnect all other external drives, except for the one you are having an issue with (just while following the below steps). Please note: that it's important to set Toolkit "enabled" as in the image below-in your Settings.

I hope this works for you:).

applenovice22 wrote:

After installing Tahoe my MacBook Pro with M2 no longer mount external hard drives and disk utility will not work either and it just shows a blank rectangle. I've installed NTFS for Mac from Paragon software which works well with the previous OS so I'm wondering if this is an issue with NTFS for Mac or is it a bug with Tahoe? There seem to be quite a few complaints about mounting external hard drive so I hope someone can help clarify.

Thanks in advance!

PS I seem to be able to find a workaround by shutting down and then starting it up again while holding the Commad R key but I don't think this is the safe mode and have the drive connected. Both Disk Utility and the hard drive shows up but if I eject it and insert it again it will not work!

Did the Paragon Software and NTFS drive perform as expected Prior to upGrading to macOS 26 Tahoe ?

Has the Paragon software been updated since the upGrade to Tahoe

It often happens that doing an upGrade to a newer Operating System may break Third Party software

https://www.paragon-software.com/home/ntfs-mac/

As for starting Apple Silicon Computer is Safe mode

You may review the instruction, specific to Silicon computer in this link

 Safe Mode. 

Psych13 wrote:

@Owl-53 I hear you, and, I, too have been using *many* external drives (successfully-once formatted for Mac) without issue. However, this particular external drive is not "playing" with Tahoe. I'm 58 years old, and like you, have much experience with both Windows PC's and Mac computers. I've had a number of external drives in the past, and have never had a problem with any other OS till now. You're implying that because *you* don't have any issues of this kind, then all is well. All clearly isn't well for many customers-you just have to read the various posts on other threads. I'm pleased it's all working fine for you, but it isn't for me.

OP also wrote " his particular external drive requires a password to unlock it (I am not using a third party software to make it password protected)-these are very costly 2T drives, which come with a password protection feature. "

I believe there are some external drives that may have a " Builtin Password " feature that is built into the Controler or Firmware that is Built into the device

ie : Samsung's T7, T7 Touch, and T9 portable SSDs are external drives that offer password protection with AES 256-bit hardware encryption.

So predicated on that singular example and ported to your Seagate drive

To reiterate

Whatever issue the user is experiencing with their Specific External Drive

It does not fall under an issue with Apple Computer or the version of macOS the machine might be running

You best to follow what has been mentioned earlier " I will be contacting Seagate on Monday to try and get to the bottom of this. "

EDITED - should you have additional issue with this drive

Suggest opening a New Question of your own

As it stand for now, OPs question has almost been hijacked

As promised, I'm updating this thread after a chat session with Seagate. As it happens, I need to install a driver on my laptop given my external drive is password protected; they said this should only be an issue with password protected drives. I downloaded and installed the App but haven't been able to test it out yet as I have another external drive connected that is in the process of completing a huge task and I need to disconnect it before I can follow through with the steps they provided me. I hope to do this by the end of the week. In case others are interested, the App (software) is called Toolkit.

Perhaps you are overlooking the most obvious

There seems to a Firmware Update from Seagate this is required to make their drive work as expected

https://www.seagate.com/ca/en/support/kb/firmware-updates-for-seagate-products-207931en/

@owl-53,

I just Google'd whether there is a firmware update and got the following reply from AI:

"There is no specific firmware update needed to make a LaCie drive compatible with macOS Tahoe 26.0.1; compatibility is managed through the host computer's operating system, not the drive's firmware. You should ensure the drive's software is compatible with Tahoe 26.0.1 by checking LaCie's official compatibility list on the Seagate website. For issues with macOS Tahoe, the primary solution is to ensure your Mac has the latest operating system updates, as the initial versions had compatibility problems with some hardware". 

@owl-53,

Apologies for yet another post but I decided to try and connect an old (and not password protected) Seagate drive to my Macbook Air and it connected just fine. So now I am left wondering whether it was the fact that my other drive was password protected that stopped it from being recognised. The thing is this: prior to me updating to Tahoe OS, I never had an issue with that particular drive, which is why I am left thinking that there is a compatibilty issue with Tahoe and my other drive.

As I said in my other post, I have tested this out with another Seagate drive and it connects and is read, just fine. But the fact that my other (same brand) external drive is not recognised/is prompting me to install a driver (despite my Google research telling me I do not need to install a driver) tells me that this is a compatibility issue-not to mention (and yes I perused the link you pasted)-that other Apple customers are having the same issues with external drives and Tahoe. How can this be a coincidence? I will be contacting Seagate on Monday to try and get to the bottom of this.

https://www.seagate.com/ca/en/blog/protect-data-with-seagate-secure-self-encrypting-drives-master-ti/

I'm having the same issue which I posted on another thread:

Tahoe not recognizing External Hard Drive… - Apple Community

Since the Tahoe update to 26.0.1 I now cannot access my Photos library which I store on an external hardrive. The drive is a Seagate drive which *was* able to be read prior to me installing Tahoe. I use a Macbook Air M2.

Psych13 wrote:

I hear you @owl-53 but how can it be that so many Apple customers are reporting the same issue? It can't be that we all have Seagate drives. I would assume others have other drives?

We. you and I, not taking about another drive than the one the user is using

https://xyproblem.info/

I think my colleague is probably " Right On "

Regarding third party software that may have been Bundled on the Seagate Drive

In the the 20 + years using Apple computers

I have acquired various Seagate drives- about 4

Some are Rotational / Traditional Platter drives while others are SSD Drives

At no time have I installed any of their Bundled Software

Each of the four drives I have, mount and perform to my expectation

Tested using a M2 Desktop, M4 Desktop and M4 Laptop each running macOS 26 Tahoe version 26.0 to 26.01

Go figure