macOS Sequoia exFAT folders randomly not visible in Windows

Question

Level 1

6 points

macOS Sequoia exFAT folders randomly not visible in Windows

As of lately, November 2025, i've noticed a couple of times that my external USB drive, formatted in exFat. Won't show folders i've made under OSX Sequoia 15.2 under Windows 11. I have this external USB drive from Seagate, a powered 4tb drive, it's formatted in exFat with cluster size of 256kb.

I've had some issues in the past, where Windows one time froze during a backup procedure and i had to do a hard reset. This caused me to lose about 160-200gb of data!!! That was back in 2020, i did a drive check and repair, after that it was again.

But since a couple of months, since we go a Mac Mini M1 using Sequoia, i see strange things happening. Sometimes, randomly, i don't see folders created under OSX show in Windows. On OSX they show fine, under Windows they simply not show.

Today i made screenshots of those folders, planning to post them here. But now I'm back at home and again, i don't see the folder i created on OSX. It seems this issue comes and goes. Ive had this before a couple of months back.

Anyone got tips or anything?

I tried looking at the parent folder, to see what restrictions or rights the admin user has on that folder. Normally we see right per user, but i don't see that in Sequoia, not for folders. I can't show it, because i can't see the drive now.

I'll try to update this post tomorrow when I'm back at work and probably, I hope, have access to those folders again

Mac mini (M1, 2020)

Posted on Nov 27, 2025 3:52 PM

Reply

Answer 1

Nov 27, 2025 11:24 PM in response to schro3f

schro3f wrote:

it's formatted in exFat with cluster size of 256kb.

macOS can be picky about exFAT formatting details so it is recommended to do the format on the Mac via Disk Utility.

I am not sure whether MBR or GUID is better. A few years ago I had better luck with MBR (Windows 10 did not display all space from a 128GB thumb drive with GUID while with MBR it display all 128 GB).

https://www.howtogeek.com/193669/whats-the-difference-between-gpt-and-mbr-when-partitioning-a-drive/

On the other hand, formatting a drive with exFAT using Windows may use a file allocation size for the file system which macOS doesn't understand. That said, I have had no problems with thumb drives formatted as exFAT with Windows 10 defaults but I have only few times used that route to transfer files to the Mac.

https://www.partitionwizard.com/partitionmagic/allocation-unit-size-exfat.html

Sonoma might have had teething problems with FAT or exFAT:

"The implementations of the exfat and msdos file systems on macOS have changed; these file systems are now provided by services running in user-space instead of by kernel extensions. If the application has explicit checks or support for either the exfat or msdos file systems, validate the applications with those file systems and report any issues. (110421802)"

macOS Sonoma 14 Release Notes | Apple Developer Documentation

Notice that some Apple's apps like Photos.app do not support exFAT formatted media -- only APFS and MacOS Extended. This is a FAQ in Photos forum when people wonder why Photos does not work as expected when the library is stored on exFAT disk.

ExFAT on HDD for FCP editing? - Apple Community

Reply

Answer 2

schro3f Author

Level 1

6 points

Nov 28, 2025 12:45 PM in response to schro3f

Ive have moved the folder to a sub-folder and now on Windows it is visible. Also created other folders today and those are now also visible under Windows 11. Super weird. I did disk repair, but didnt see anything concerning. Didnt get any flags of possible wrongs

Disk utility result

Main disk info

Folder now visible under windows after i moved it to a sub-folder in that folder where it earlier was not visible

Reply

Answer 3

schro3f Author

Level 1

6 points

Nov 28, 2025 7:24 AM in response to schro3f

Okay, im at work and now see the folders again. Here are the screengrabs of those folders.

Reply

Answer 4

schro3f Author

Level 1

6 points

Nov 28, 2025 7:31 AM in response to Matti Haveri

I think i even formattted this drive on MacBook Pro initially, the drive is old, believe its from 2017 or so.

Ive used this format perhaps for a decade now, never had these issues with older OSX. At work my old Mac Pro from 2009 was running El Capitan and never had an issue. Since i got the M1, im seeing these issues. I can not simply format the drive unless i get another drive. It holds to much data to transfer at the moment.

I was hoping some would show perhaps tips.

Perhaps i should run fsck or something

I have other folders created on the drive from the same day. Those do recide in a different sub-folder, but they show up just fine in Windows. Its hit and miss with this issue.

Im also having Spotlight issues where spotlight server stops all the time. Have done dozens of methods getting it to work, without any working. It simply stops after a while i reboot the system. It cant be that something with that is related to this, right? Would not make sense if it does

Reply