Sequoia 15.0 bugs - external hard drives

I have finally found you!!! After years of searching, going to several Apple and repair stores, being utterly frustrated on line with tech support and most importantly, losing several external drives as well, this thread with others in the same position finally revealed itself. As we are into 2025, and I have owned two 2022 MBP's that have both corrupted ex drives with no explanation or fix. I have stopped using any traditional ex drives on it and use only thumb drives or air drop to transfer files to a 2013 MBP w/ two USB ports that connects all other drives. I have had to duplicate backups on several drives after permanently losing more than 5Ts of photo/video/web content after connecting drives to this MBP - regardless of hub use or not. They have failed catastrophically and I haven't understood Apple's deafening silence or lack of ability to assist us. We are mostly all long-time users who have come to expect a high level of compatibility between our readers, drives, editing programs and phones and have invested significantly in Apple products from the late nineties till now. The product cost has not decreased, while you deliver something that causes irreparable damage to our valued output, with no solution??? You must do better. Considering using a cloud service before I lose the refurb 2013 that has remained a work horse far longer than it should. But thank God I have it or I would really be screwed. Have been scared to plug in a drive since this last update since the one before, after successfully using 2, 1T ex drives to jump between my mac's for several months, they too suddenly stopped working and only one has successfully resuscitated!! I am ENRAGED what gives?? Just tell me what not to do and I won't, but please ACTUALLY ACKNOWLEDGE THIS IS A PROBLEM, say something AND FIX THIS PROBLEM.

[Edited by Moderator]

Apple! You have been my "rock" since the 1980's. My rear window carries the apple sticker because I've made a living off of my Apple computers.

I just turned 70...and purchased what may be my last Apple. A new 27" monitor, and a new iMac Studio with plenty of ram to run Adobe software, so I can continue to create graphics, and stay up to date with the OS.

The new iMac started glitching. Bright magenta screen, Adobe programs going blank, having to restart continually. My external used for Time Machine backup was full of older art files as well...so I also worked with an Apple specialist who after hours of investigating (which included re-installing the OS) realized my external was failing. I tried to mount the external to my 2017 iMac with Ventura OS, (which had worked fine for several years) and it will not mount.

However, my new iMac seems to be working fine since removing the external hard drive.

I chalked it up to the external failing. Did some investigating on recovery methods, and it most likely will need to be shipped out at great cost to get those older files off of it.

Last week I purchased a new SanDisk Extreme 2TB for Time Machine backups. It worked for 3 days. I checked it yesterday, and have a new message that says: The disk “My Backup” can’t be unlocked. A problem was detected with the disk that prevents it from being unlocked. Attached is a snapshot of the new external Disk First Aid check.

I have reached out to the Apple technician who is familiar with my former case, and am still waiting to hear from him.

Apple, please give us all an update on this BUG. Steve Jobs would not be happy right now. Neither am I. Apple is costing us money instead of making us money.

A solution that helped me with SSDS on M4 Pro: Format external drive to ExFAT, and drives return to normal to normalish speeds.

So I had the same or a similar issue that could be resolved with the Apple Support Team.

Situation: Abysmally slow external SSDs (worst case 8MB/s write) connected directly to USB C port to MacBook Pro 16" M4 Pro but were fast on MacBook Pro 16" Intel?!? My Samsung T7 randomly ejected on my old MacBook but not on my new one!?! Bro idk...😀🥲😭

Hope this might help some of you 🥺

Kindest regards

Stranger on the interwebs

Tinx_Lvs_JC wrote:

Same problem! Since Sequoia, none of my ports/drives work so can't back up, can't use separate mouse/keyboard, can't use Thunderbolt. Did some research and have attempted everything that is within my ability BUT I can't do anything to do with coding. Apple - please fix this bug! It's a crucial issue.

This is a user-to-user forum. Apple does not monitor the community. If you want to make a report contact Apple through this link: Contact Apple Support

Latest Sequoia update has sorted the port problem for external hard drive - YAY!

My Time Machine external hard drive still works, but my three other external disks (Macintosh formatted disks) do not show up on my desktop or in disk utility. Spent hours on the phone with Apple support - tried most everything with no result. Booted up in safe mode, booted up in test user, restarted several times, disconnect and reconnect the disks, etc. No result. These disks worked fine before Sequoia. Naturally, the Apple technician said it was a hardware issue with the disks - very Microsoft of him. Suspect a software issue.

AlWeir wrote:

Was reading this morning that HFS+ volumes are not supported in Sequoia.

According to Apple's documentation, Sequoia supports HFS+.

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

Not so.

Time Machine still fails on my Mac as it does almost every year with new OS releases these or similar issues with my external drives and/or Time Machine, Disk Utility, Spotlight (and even 3rd party software like Carbon Copy Cloner) consistently reappear.

Year after year.

Yesterday, 12/19/24, 9to5Mac released an article that confirmed macOS bug(s) most-likely related to most (if not all) of the issues that we are reporting here.

Here’s my humble suggestion.

Demand Apple fix the issues once and for all. That’s the only solution.

Write excellent software like they did under Steve Jobs. We know they can, but will they? This from The Ghost of Christmases Past.

Merry Christmas!

My Mac Mini M4 came with Sequoia pre-installed so there was never any other OS on it. Yet my external drives are still randomly disconnecting. It happens several times a day. It has nothing to do with how many previous versions of the OS you have had installed. Most people did not have this issue until updating to Sequoia.

Same problem for me. Multiple older backup HDDs are not seen by the system, including Disk Utility. My backups are two weeks out of date, as of this message. For me the problem was not linked to an upgrade or a dot version OS update. I bought a new Mac Mini M4 in late November. External drives mounted fine, and both Time Machine and CCC ran normally. Sometime over the evening of Dec. 31, it all stopped. I had been on 15.1.1 for over a month, and was yet to update to 15.2. Why the failure happened without any evident change in the OS is a mystery. Having spent a fair bit on the Mini and monitor/peripherals, I am loath to buy backup disks, so this is missing piece is critical for me.

I feel your pain. Since, at least, the initial release of macOS Sonoma, I have had nothing but trouble keeping access to my SanDisk USB 3.0 (USB-C) drive. If Time Machine isn’t failing, Disk Utility is.

There have been countless complaints about connection issues (bugs and possible decagon flaws) in macOS with regards to USB-C drives for years now.

Apple appears either incapable or unconcerned about the myriad of issues with macOS and external USB-C devices.

I have had USB-C external drive connection issues since, at least, Sonoma, I am thinking as far back as Monterey. Disk Utility, Time Machine and other software have, at times, been unstable or virtually useless.

Now, since Apple Intelligence was released, CleanMyMac X fails to complete exhaustive scans, apparently because Spotlight (or its associated utility software) is constantly indexing my internal and single external (Time Machine) SSDs.

Time Machine sets that off as far as I can tell. Every hour, Time Machine backs up my 2021 M1 iMac, which sets off more indexing.

So it never stops, at times, radically slowing my system down and interfering with software performance and I/O while consuming memory as well.

I believe Apple knows about this and either can’t or won’t resolve the USB-C issues on M series Mac’s.

There seems to be hundreds of people mentioning similar and likely related issues on these forums as well.

Good luck.

For me, I did not have a problem with Sonoma or any Mac OS before Sequoia.

I can eject HFS+ journaled external HDs but not APFS or Ex-FAT USB C SSDs - even if I go and force quit everything and restart Finder, Sequoia reports that "an application" is still using the external drive.

This needs to be fixed ASAP.

Same. But after updating to 15.3 my external hard drives don't show up at all. They will trigger applications, but won't even show in Disk Utilities. The main hard drive won't show there either when an external drive is plugged in. When I disconnect the external drive it gives me an error that the disk "can't be unlocked".

Wish this was a fix, but it's not. (Plus, the instructions for resetting the SMC controller on Intel-based desktops differ from what's posted.)

This bug, which seems to have been around at least since Sonoma, manifests differently across machines, is not confined to any one type of connection/cable and, unfortunately for the purposes of escalation, isn't a global issue.

It is, however, persistent and a major pain. (Note: after 15.3.1, my external drives are now all working, but two of the three—the USB-C drives—will not unmount.)