7 solutions to fix "The disk you inserted was not readable by this computer"

By Katrina | Posted to Mac Data Recovery, updated on March 26th, 2019 |

Summary: This is the most comprehensive guide to fix "The disk you inserted was not unreadable by this computer" on High Sierra/Mojave. You will learn everything you need to know about this issue, from possible reasons to effective preventions.

Table of contents
1. Problem - "The disk you inserted was not readable by this computer" on Mac
2. How to fix "The disk you inserted was not readable by this computer"?
3. What causes "The disk you inserted was not readable by this computer" error on Mac?
4. Tips for avoiding the disk not readable error on Mac
5. Conclusion

Problem - "The disk you inserted was not readable by this computer" on Mac

Some users are complaining that they fail to access an external hard drive, USB flash drive, SD card, memory card on Mac with an error message thrown out, mentioning "The disk you inserted was not readable by this computer". Here is one user statement we just extracted from community.spiceworks.com:

In case things get messy, I made a backup of all my previous data on an external hard drive before upgrading to macOS High Sierra. But after successfully upgrading to High Sierra, the backup disk didn't initialize. I got the message: "The disk you inserted was not readable by this computer." To avoid data loss, I clicked "Ignore". Can anyone tell me how to fix this issue on High Sierra?

The disk you inserted is not readable by this computer on on High Sierra

Note: Under this circumstance, if you didn't back up important data, please do not initialize the drive. Because this action will erase whatever's on the hard drive, making it extremely difficult to recover your data.

Fix "The disk you inserted was not readable by this computer"

There are 7 solutions for you to fix an external drive not readable by this computer on macOS Mojave/High Sierra. Just try them one by one until you find the one that works for you.

You can also watch this video tutorial to fix this error:

Solution 1: Re-insert the drive

First of all, you can remove the hard drive safely from your Mac and then re-plug it properly. Then you can try accessing the drive to see if the error persists. If the error message still continues to appear, move on to try other methods.

Solution 2: Check the Mac computer

To save you from trying out a lot of potential fixes for nothing, you should make it clear whether the error results from the Mac machine or the storage device.

  1. Option 1: Connect a different external drive into your Mac computer, if you can see it in Finder, it should be the external drive's issue. If you don't get the same error with the other drive and it lists inside the Finder app normally, you can exclude that the problem is caused by your Mac. The problem is associated with the previous external drive.
  2. Option 2: If you have another computer available, insert the hard drive to in to check if it works. If the drive doesn't work on another computer, there is something wrong with the device.

Solution 3: Check if the drive is encrypted

The disk not readable error can occur if the disk is encrypted using BitLocker in Windows platform. This is because the Mac doesn't support BitLocker. When you connect a BitLocker-protected drive to your Mac, you will receive "The disk you inserted was not readable by this computer" error.

You can insert the drive in a PC and then turn off the BitLocker encryption so that it can be read on Mac.

Solution 4: Check the file system

Check the file system of the external drive to see if the file system is readable on Mac. If it is the file system that Mac isn't compatible with, it should be the reason why the disk is not readable on the Mac.

To check its file system, open Disk Utility from your /Applications/Utilities folder. Then select the external drive in the column on the left. At the top right corner, click the "Info" and you will see Format.

Solution 5: Update Mac drivers

The disk not readable error can also be due to the outdated driver on Mac. You can check the drivers on your Mac and update them by the following steps:

  1. Step 1: Go to Apple menu and select "App Store".
  2. Step 2: Click on the "Updates" button located on the top pane.
  3. Step 3: Check available updates for your system and applications.

After these three basic checks above, if you still get "The disk you inserted was not readable by this computer" error, you can be sure that it's caused by logical corruption of the external drive. Just follow the solutions below.

Solution 6: Repair the unreadable external drive in Disk utility

Disk Utility's is a Mac built-in tool to format, manage, verify and repair certain disk problems. It's helpful for you to fix many drive issues including "The disk you inserted was not readable by this computer" error.

  1. Step 1: Open Disk Utility from your /Applications/Utilities folder.
  2. Step 2: Select the unreadable drive in the left side bar.
  3. Step 3: Select the "First Aid" tab.
  4. If Disk Utility tells you the disk is about to fail, back up your data and replace the disk. You can't repair the disk. Otherwise, continue to step 4.

  5. Step 4: Click Run.

Repair unreadable hard drive via First Aid

If Disk Utility reports that the disk appears to be OK or has been repaired, you're done. Otherwise, you have to back up as much of your data as possible.

Solution 7: Initialize the unreadable external drive

If the error still exists, you have no choice but to click the "Initialize" button. But keep in mind that you will lose all your data on this disk. If you care about files on the disk, you should at first perform data recovery with High Sierra compatible data recovery software, like iBoysoft Mac Data Recovery.

iBoysoft Mac Data Recovery is reliable and easy-to-use data recovery software that can recover data from unreadable external hard drives, hard drives, USB flash drives, SD cards, memory cards, and digital cameras, etc. It supports file systems including APFS, HFSX, HFS, HFS+, exFAT and FAT32. Besides, it can recover deleted files even emptied from Mac Trash, recover lost data from formatted, unmountable, inaccessible, corrupted drives on macOS Mojave 10.14/High Sierra 10.13/Sierra 10.12 and OS X 10.11/10.10/10.9/10.8/10.7.

Step 1: Recover data from the unreadable external drive with iBoysoft Mac Data Recovery

1. Download, install and launch iBoysoft Mac Data Recovery. On the home interface, you can see all connected devices listed.

Recover data from unreadable drive with iBoysoft Mac Data Recovery

2. Select the unreadable external drive and click "Next". The program starts a quick scan to find files on the unreadable drive.

Recover data from unreadable drive with iBoysoft Mac Data Recovery

3. After previewing the scanning results, choose files you want, click "Recover" and specify a different location to restore files.

Recover data from unreadable drive with iBoysoft Mac Data Recovery

Step 2: Initialize/erase the unreadable disk

1. Go to Applications > Utilities > Disk Utility.

2. After launching Disk Utility, choose "View" from the upper right menu bar. From the drop-down menu, select "Show All Devices".

3. Select the unreadable disk in the left side bar.

4. Click the Erase tab on the top of the window.

5. Enter the related info and click the "Erase" button.

After the formatting process completes, the unreadable external drive will work as normal again. Then, you can copy the recovered data to the original place.

What causes "The disk you inserted was not readable by this computer" error on Mac?

There are various reasons behind "The disk you inserted was not readable by this computer", let's take a loot at some of the possible reasons for the same:

  • Human mistakes
  • Faulty connections
  • Mac malfunctions
  • Virus attack
  • Drive corruption and bad sectors
  • Incompatible file system format
  • Improper installation of programs

Tips for avoiding the disk not readable error on Mac

As the saying goes: the precaution us better than cure. To avoid this error, you should follow these helpful tips:

  • Take a complete backup of all important data and update it often
  • Install anti-virus software and scan your hard drive routinely
  • Always remove external drives safely
  • Be sure to shut down your Mac computer before the battery wears out
  • Run Disk Utility's First regularly to check and repair bad sectors

Conclusion

Hopefully, these solutions have fixed "the disk you inserted was not readable by this computer" error. It's worth mentioning that if you can't find your important files, iBoysoft Mac Data Recovery is the best free data recovery software to deal with different data loss problems.

Which solution works for you? If you have any question, please feel free to contact us via email. Also, if you think the article is useful, share it with your friends and families on social media. Thanks in advance!

Katrina

Katrina is a data recovery expert @iBoysoft who loves to help readers solve various data recovery problems.

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