'The disk you inserted was not readable by this computer'

i have 2 480GB Ultra II SSDs docked into a OWC thunderbolt 2 dock connected to my iMac. Everything was working well, until myteriously, my Mac frozed, and so I did a hard reboot. When the iMac came back on, everything seemed fine. However, I srated getting this message from one of the SSD drives docked. ‘The disk you inserted was not readable by this computer.’ 

I have data on it which I have no back up for. and I am hoping that there is a way to recover the information on it. How can i recover the data? 


Hi, Please contact our support center for any concern on your data, our agent will suggest data recovery service to you.

Im guessing you have already tried repairing with Disk Utility - if this is a boot drive, you will need to boot into recovery mode to repair it. I see the disk uses MBR instead of GPT. Is this an ExFat drive or is it OS X HFS+?

Most likely you “bricked” the SSD with the hard reset. With SSDs that lack their own dedicated power backup, they are prone to data damage from a power failure while writing. Most consumer level SSDs have limited or no protection against this type of damage because it can raise the cost substantially. For example, many Intel SSDs (arguably one of and possibly the best SSD maker) have full built-in power loss protection, but many of these drives cost twice as much as standard level consumer grade drives.

If this drive is currently still used through a SATA–>ThunderBolt interface, you will want to connect it to the SATA port. Then, try booting into the OS X recovery drive and attempt to repair the disk. I’ve not done this with ExFAT drives, but with HFS+ drives I was unable to repair going through a USB interface, I was able to repair them upon connecting them directly to a SATA port.

Have you pulled any SMART data using something like Crystal DiskMark or DriveDX? This can give you a good idea of what happened.

If repairing through a SATA interface fails, my next step would be to send the SSD power without data and wait. IIRC, the Ultra 2 uses the same controller found in Crucial mainstream drives. With these Crucial drive’s, the first action with a bricked drive is to generally plug the SSD into a SATA power source, but DO NOT send any data to it. Providing the SSD with power but not sending it data will create downtime allow the SSD controller to perform several actions, some of which might repair the disk. From a time perspective, give it at least 24 hours. During this period, the SSD should become a little warm to the touch even though you are not sending any data to it, which indicates that the SSD controller is at work.

If that does not work, you could try a data recovery program, but it should be noted that your odds of success with most products are not great, and it’s rare for these programs to be able to recover all data. As a general rule, data recovery is expensive and the data recovery that comes with most drives’ warranty is very limited, with the exception of the premium enterprise-grade HDDs and SSDs.

I am guessing this is not a drive formatted in HFS+ (OS X Extended Journeled), but if the screenshot is a typo and it is, you have a HUGE advantage. There is an application called Disk Warrior and it is the tour-de-force of data saviors. It can repair severely corrupted drives that are way beyond the point for other programs to fix. However, I have an older version that will not repair ExFAT, and the current versions may not support ExFAT, NTFS, or FAT32. While comparable software may exist for those formats, I am yet to see a Windows product that can rebuild a drive anywhere near as well as DiskWarrior.

What causes The Disk you inserted was not readable by this Computer?

The core reason for the disk is unreadable by this computer error to occur is corrupted or damaged drive directory, which may be caused to any of below:

  • Viruses and Malware.
  • Errors in the internal file system.
  • Corrupted Catalog file.
  • A forceful restart of the computer system.
  • Switching off the computer system without the proper method.
  • Faulty connections.
  • Mac malfunctions.

How to fix “The Disk you inserted was not readable by this Computer” Error?

Solution 1: Using First Aid:

Solution 2: Using Erase:

Solution 3: Change the Drive Format:

Solution 4:  Initialize on New hard drive

Solution  5: Recover data using Bitwar Data Recovery for Mac

How to Prevent “The Disk you inserted was not readable by this Computer” error?

  1. Always eject the external drive, e.g., USB flash drive, SD memory card, and external hard drive safely or adequately. If the external drive in use is ejected/removed unsafely, it can get easily corrupted.
  2. Apply advance file system by using NTFS/APFS etc. for storing extensive data.
  3. It’s a great practice to create a backup of all your relevant data on regular intervals. You can use Time Machine by Mac to help you in creating backup automatically.

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