Why do I get "Disk not ejected properly" error?

I updated my 2018 mac mini to monterey 12.3.1 and started getting the disk not ejected properly error too. Tried everything I could find here on the internet and nothing worked. I had been running a WD 4TB hard disk formatted for Time Machine use and it had been working perfectly for several years. After exhausting all the remedies here I decided to VNC into my mac mini and see what that login looked like. To my surprise I got NO disk errors at all. I then logged into my mac using the root login and again no disk errors. This ruled out cable and hard drive issues and pointed back to the user account. I spent a day and half deleting cache files and resetting pram and nothing cured my disk not ejected properly issue. So what I did to fix my machine was made a complete current backup with time machine then setup a new user account with admin rights. I logged in with the new user and deleted my original login account. I shut down and restarted my mac in recovery mode and reinstalled monterey. Once monterey was reinstalled I logged into my account and used migration assistant to restore my mac with the backup I had made. The backup restored my original login account which purged whatever was causing the disk not ejected properly error. Once I was able to login with my original account and verified all my files were intact I erased the second user account I had setup. So far it been 24 hours and the computer has went into screen saver and shut the power off the monitor several times with out any errors.

Hope this helps others as its helped me!

So, I have 2-3 solutions for your Problem - starting with

👉 did you plug in your hard disk in iPad or any other computer - does it show your drive content, if not showing it means SSD is not in working situation any more better to send to Samsung as they are offering a year warranty don’t have idea for sandisk. I’m sure for Samsung bcz I sent mine ssd to them for a data recovery.

👉 How to avoid it’s happening again! - when you put you Mac to sleep then automatically SSD goes in stand by power and when you awake screen it start working as usually without a pop up “Disk not ejected properly” if you still showing this notification then turn your SSD from APFS to mix formate exFAT I’m using since a year have no problem at all and plus point you can plug it in both windows and Mac machine.

👉 But as per my perspective we need not to eject every single time unless SSD is in work or any folder is opened and any task going on background using data from ssd. So better to close every single process associated with SSD and then put your Mac to sleep and whenever you will turn it on it won’t show you that message. It pops up only when you put Mac to sleep and task is still going in background using ssd data. Else I never saw this notification since I close all the tasks.

In the Battery Preferences do you have an entry about powering off HDD or similar?

SInce this only happens with some drives it does not seem to be a general problem so it may not be Apple's problem.

ALso, based on discussions in this forum it seems dependent on the electronics in the enclosure for the drive since some users have eliminated the problem by using a d8fferent enclosure.

You listed 12.2 as your acOS forum. 12.2.1 was released 2/10 so update if not already there

Enver Masud wrote:

How does one put the SSD to "sleep"? Who is responsible for fixing the problem? Sandisk, Samsung, Apple? Has anyone taken responsibility? The screen saver is set to start automatically.

Many have had this issue. For now turn off put drive to sleep and just use a screen saver.

Set "turn display off" to never. I believe this is an Apple OS issue as this did not occur in the previous OS releases.

I've only had my Macbook a year and a half. I had no issues until I updated the OS. I was hoping the Big Sur OS update would cure the problem but it hasn't. I've completely erased my Macbook and reinstalled the OS and started everything over from scratch and it still disconnects my external hard drives and it's extremely infuriating when transferring large files because I have to start over from the beginning. I've changed all the sleep settings, etc that I've seen other people mention and nothing has worked. It definitely is an issue with the operating system and I have no idea how to get Apple to FIX THIS! Nothing suggested permanently fixes this issue and the fact that Apple doesn't know how to fix it is ridiculous.