Mac OS Sequoia not recognizing USB Flash Drives

Brian Williams2 wrote:

Hi. You wrote "Allow accessories to connect,". I am on 15.0.1 and cannot find this option in Privacy & Security. Apple documents say it's there, but I don't see it. Where did you find it?

I believe that option is only available on the M-series laptops. The M-series desktop systems I don't believe have that option, nor do any of the Intel Macs (laptops or desktops).

DavidWMB wrote:

I reported the matter to MacOS Feedback, but Apple hasn't bothered to respond.

You did well to report it. There is never a reply unless they need further information. That's normal procedure, all feedback is read but usually they do not reply. The more people join their voices with respect to a given issue, the more likely it is to be fixed sooner.

MJ wrote:

dwiser12u wrote:

I had to go through Apple Support. They say they don't have any history of this issue with updating to Sequoia.

That's bogus. Either Apple is lying or they maintain very crummy records.

Or very few people actually made official requests for support and asked for their support request to be escalated if the first line techs are unable to fix the problem. I think you over estimate how many people actually do this. I think many people just post on the forums thinking that will get Apple's attention.....it won't since Apple is not here on these forums.

Same here. I have a 4TB M2 drive mounted in an Acasis enclosure and then through a Kensington SD5700T Hub.

This worked perfectly fine without fail until update to Sequoia.

All hub ports and other connected hardware show in USB hardware report. The 4TB drive does not mount.

If I unplug the drive to hub or even the hub to Mac connection it appears as soon as they are connected.

Has anyone rolled back to Sonoma and its fixed the issue?

[Edited by Moderator]

On MackbbokPro M1, on Sequoia, One Drive on my Sat Nav (SD64), comes up unreadable, but shows in diskutility and can be mounted. However the main sat nav drive is greyed out and says uninitialised...however both work normally on an intel based 2019 27" iMac ... obviously I cannot reformat a Sat Nav drive, so no cannot update routes when travelling.

What a mess they made of it... any suggestions?

Sequoia also fails on both intel iMA and M1 macbookpro, when copying very large folders (with thousands of files), with error 50, every time. However on a Sonoma macbookair it works every time, for the same folder, on the same drive, on the same network.

I confirm critical erratic behavior for ALL my USB devices plugged on my macbookproM2 after upgrading to Sonoma and complete blocking after upgrading to Sequoia. Never experienced such failure since my Apple II+. Prior focusing on IA may be more wiser fixing these USB issues.

I have a different problem - my USB flash drive loads just fine, but it's always UNTITLED as the name - and I can rename it and it won't hold the name after I pull it out and reinsert it. Every flash drive I have does this. Load that flash on another Mac and the name is always there. This is on an M3 and I just updated to 15.2 and it still does it.

mwhdvm wrote:

I have a different problem - my USB flash drive loads just fine, but it's always UNTITLED as the name - and I can rename it and it won't hold the name after I pull it out and reinsert it. Every flash drive I have does this. Load that flash on another Mac and the name is always there. This is on an M3 and I just updated to 15.2 and it still does it.

Please start a new thread, and include more information about your setup.

Please also include an Etrecheck report so we can look for possible causes.

I am having the same issues. New 2024 MacBook Air, M3 chip. SanDisk USB C Flash drive. It started to back up the first time I connected and failed to complete the back up. Now, I cannot get it to mount through disk utilities. Can see it greyed out. I can see it under the USB connections in system information. But, I'm stuck. Running Sequoia 15.1 Is there a fix for this?

Since updating to Sequoia 15.2 my MacBook Pro doesn't recognize USB flash drives or Midi devices, even with doing all troubleshooting it will not recognize. Connected those same devices to another computer with Sonoma and all the devices were recognized. Has anyone found a solution for this? this is such a pain

Sequoia 15.2

Someone has already reported it works only once. I have the same situation – mounting remote controller FrSky Teandem X18S works seamlessly only the first time I plug it into the Macbook. All attempts after that fail.

me too. I took a bunch of data off an old macbook pro with a busted screen, and now I can't even get the usb drive to connect to my new macbook pro using the same dongle. Pretty pathetic, and frustrating.

This is still a problem under 15.3.2

For me, the issue is intermittent dismounts of ALL USB drives, not just flash drives.

What REALLY drives me nuts is that these external drives all worked flawlessly under Sonoma ... so obviously Apple changed SOMETHING when moving to Sequoia.

Which setting is that? I'm not finding anything that looks like that in Settings.

Edit: It looks like maybe you can only see that setting on laptops; I don't see it on my Studio. If your Mac asks you to allow an accessory to connect - Apple Support

OTOH, on my new M4 Studio I have not yet had any issues with my Garmin failing to connect. Rather an expensive solution to that problem but I'll take it.