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

Me to.

My Crucial X10 Pro will not mount on my Studio.

And attempting to format in APFS with Disk Utility causes rejection.

It did however mount as Ex FAT, even copied small files ( 25mb photos ) but if tried to

copy a large file of 915mb such as an MP4 movie ( Chose Psycho as seemed appropriate ),

it did a Mr Bates and Ejected from Desktop.

Further attempts to erase/format unsuccessful.

Interestingly , my other 2TB Sandisk SSD's are humming along.

So far not impressed with response/suggestions from Crucial.

Luckily I had just backed up ( updated the backup) to the old fashioned WD 6TB drive the night before (my System Photos Library 1.3 TB was on the Crucial ) and thankfully also on a older Sandisk 2TB SSD.

Had the issue as well this morning. Tried all of the suggestions here, nothing worked.

Connected to a PC, was detected as having errors so I selected "Fix and Repair" on Windows 11. After that connected to my M1 Max Mac with Sonoma 14.6.1 and it is again recognized and working.

I found to my great relief my x9 was opened no problem on my old laptop that hadn’t been updated. Then back to my newer MacBook and there it was again! Has worked perfectly since. So try that . I’ll put the kettle on.

As an update to my previous post, I now have a 2 TB Crucial X9 SSD serving as my reliable Time Machine backup drive on Sequoia 15.0.1 on an M2 Mac mini Pro. It is directly connected to the mini. I also have a 1 TB Crucial X9 Pro being used for non-TM purposes. Both drives are formatted as APFS, and at one time, I also had the X9 Pro formatted as FAT32 without an EFI partition. In all cases, these drives purchased directly from Crucial have worked flawlessly.

I keep the version of macOS current on my Macs and those using outdated operating system versions should update to the last available, since Apple does not exhaustively detail bugs that they fix in the updates/upgrades.

I'm adding my drive to the list - Crucial X9 SSD 4TB that seems to only appear when it pleases, and also randomly unmounts itself. Data seemingly unaffected. This is a brand new drive. My Macbook doesn't have USB C ports so I assumed the fact I'm using other cables could be part of the issue, but the symptoms seem identical to others described by users here. Will be keeping an eye on the thread for a fix!

I am having this exact same issue. I've had this SSD for less than three weeks and have irreplaceable data as well.

Please, Does anyone have a solution to this problem?