Crucial X9 SSD not showing up after update to Sonoma 14.3.1 - MacBook Air M2

Any new developments on this issue? my Crucial X9 pro 4TB started disconnecting itself a few times for a couple days connected to my Mac Studio, I'm using the factory cable and its formatted as APFS in Sonoma, now it decided not to mount at all. any updates on this issue?

I have the same issue, and it started after a re-boot a few days ago, I have 3 crucial ssd drives and 2 won't mount now (even though the 2nd one did Saturday), when re attaching for 2nd time, its a "computer says no" and i cant believe 2 drives of different age would fail., so must be something switched or an issue with software. same lights as above, so power ok, and i thought no moving parts in ssd so am guessing its software. Disk Utility wont run first aid and cant mount them either. On Sonoma 14.4.1 I hope this can be fixed soon?

Update this morning - 1_ its definitely not teh crucial ssd as it works on other devices i tried, 2_ the person who suggested opening safari is a genius, not sure how or why, as i use another browser as my default, but i opened safari, navigated to a single page, then mounted one of the ssd drives and bingo, found it and can read it....how weird!! by the way i also couldnt attach my iphone to synch with itunes and update software for some recently downloaded media, but i will leave that for later but as it it linking via usb-c ports to M3 macbook pro i suspect its teh same post sonoma issue, but am happy today with the ssd "success" for now....hope this also helps one or two of you...

Use the Crucial drives with the USB-C 3.2 Gen 2 cables that ship with them. Connect them directly to your M2 Mac USB-C port, not through a hub. The drives are pre-formatted as exFAT and to realize best performance with Sonoma, should be formatted APFS. You also have either a 3 or 5 year drive warranty, and if you purchased them directly from Crucial, you may be able to return for a refund or replacement.

I use Crucial X8 2TB drives here formatted as APFS and exclusively for Time Machine or as a drive for Parallels's guests. Been using these Crucial drives without issue for 2+ years.

I'm having a similar issue. Using a Crucial X9 Pro on an M3 MacBook Air running Mac OS Sonoma 14.5. Just purchased this hard drive 2 days ago and transferred a huge amount of irreplaceable files to it. Today it started popping up input/output error messages. I ejected it and reconnected it and now it won't mount. Disk Utility is showing it, but it's grayed out. I'm keeping my fingers crossed that someone has some sort of solution for this, because I'd be devastated if I lost some of these files.

Same here, literally started the second after I updated macOS to 14.5. First time I could fix it with first aid.. in Disk Utility but now it fails even that.

Crucial X9 4TB.

I am using my Crucial X8 on macOS versions : 14.3.1, 13.6.4, 12.7.3 , and 11.7.10 without issues. If your mounting problems are restricted to the relative new X9 product, I would check with Crucial to see if they have a firmware update for it, or can offer any other suggestions for your circumstances.

I am having the same problem.

I'm getting this also. 4TB X9 Pro - Sonoma 14.5 (23F79)

When I connect the SSD it blinks slowly 3 times with the white LED, the goes on solid, but can't be read.

Try another computer

Yes weirdly I have an x6 and and x9. The x6 gets recgnised (it's just for time machine backups) but the x9 is nowhere to be seen despite having all my iMovie stuff on there as I'm using it as my working drive for iMovie to save filling up yet another laptop. I've swapped cables and various ports but no sign of the Crucial x9. I think I'll need to just send it back and see what they can do. It's not as if they're cheap so you expect them to work. I'll try another brand next time.

My x9 still had not been recognised by my MacBook even after being left on all night. I swapped it around and still no joy. BUT I clicked Safari (I was about come here again to comment) and maybe it was s coincidence but the x9 has appeared on the desktop and opened when clicked! I’m almost frightened to unplug the little b&gger.

OferFox wrote:

I'm having a similar issue. Using a Crucial X9 Pro on an M3 MacBook Air running Mac OS Sonoma 14.5. Just purchased this hard drive 2 days ago and transferred a huge amount of irreplaceable files to it. Today it started popping up input/output error messages.

I certainly hope you have a backup of this data. You should never have just a single copy of any important & unique data. In fact the more important the data, then the more backup copies you should have.

If you don't have a good backup of this data, then I highly recommend you get a good backup very quickly.

I ejected it and reconnected it and now it won't mount. Disk Utility is showing it, but it's grayed out. I'm keeping my fingers crossed that someone has some sort of solution for this, because I'd be devastated if I lost some of these files.

We don't have enough specific details about your system and this external SSD (Crucial does not make hard drives). There are so many possibilities that you really should start your own thread so that contributors do not get confused when trying to assist you. Information we need, the exact model of the MBAir (Apple menu --> About This Mac), partition & file system used on the X9, how you erased the X9 prior to using it, are you using any proprietary third party Crucial software to manage this SSD? Also, macOS configuration settings such as whether you are allowing or disallowing external drives to sleep. Plus when does this drive tend to eject? Any patterns on what is happening with the laptop when this occurs? Waking the laptop? Using certain apps? How is this external drive being used? Perhaps it is a compatibility issue with another connected device. This is why your own thread is best, but feel free to monitor this thread for any updates if the OP ever responds back here. You can also post a link to this thread as a reference to other users with a similar issue.