How to Fix the Disk is Unreadable Error on Mac?

Posted by Molly to Mac Data Recovery on August 6th, 2018

I keep seeing the error message "The disk you inserted was not readable by this computer". Can initializing fix the unreadable disk? I have important files on that disk which I don't wanna lose. So, do you know how to fix the not readable disk on Mac without data loss?

In this article, we will walk you through the possible reasons that may lead to "The disk you inserted was not readable by this computer" error. More importantly, we will tell you how to fix the disk is unreadable on Mac.

Why the disk is unreadable on Mac?

"The disk you inserted was not readable by this computer" error usually occurs to external disks such as external hard disks, USB disks, SD cards, memory cards, Pen drives, etc. This will prevent you from accessing the files on that disk. Many reasons can make a disk unreadable on Mac, from damaged catalog file, file system errors to sudden power off, virus attacks or improper operations.

Troubleshooting tips for unreadable disks

1. Re-insert the disk to check if it is the issue of the connection.
2. Make sure all the Mac drivers are up-to-date.
3. Plug in the unreadable disk to a different Mac to check if the disk is readable on that Mac.

If you are sure it's the disk's issue, then follow the solutions below to fix the unreadable SD cards, USB flash drives, memory sticks, external hard drives, etc.

How to fix the disk is unreadable error on Mac?

Solution 1: Fix the unreadable disk in Disk Utility

Disk Utility's First Aid is able to verify and repair disk errors when the disk is unreadable, unmountable, unrecognizable, etc. on Mac.

Step 1: Go to Applications > Utilities > Disk Utility.

Step 2: Select the unreadable disk.

Step 3: Click First Aid on the top of Disk Utility window.

Step 4: Wait till the reparation of the unreadable disk process finished.

Solution 2: Fix the disk is unreadable on Mac error by initializing

If Disk Utility failed to fix the unreadable disk you inserted, then you have to fix the unreadable disk by initializing, just as Mac suggested. But before that, you'd better make sure you have a backup of all the files, or recover data from the unreadable disk with the help of reliable data recovery software, like iBoysoft Mac Data Recovery.

iBoysoft Mac Data Recovery is able to recover data from unreadable external hard drives, recover data from unreadable USB flash drives, recover data from unreadable SD cards, recover data from corrupted external hard drives on macOS Mojave/High Sierra 10.13/10.12 and OS X 10.11/10.10/10.9/10.8/10.7. Besides, it's the best APFS data recovery software that is able to recover files from lost, formatted, corrupted, encrypted APFS drives/partitions.

How to recover data from unreadable disks and fix the disk is unreadable error?

Step 1: Recover data from the unreadable disk with iBoysoft Mac Data Recovery.

1. Download and install iBoysoft Mac Data Recovery.

2. Launch this program. Select the unreadable disk and click "Next". The program will start scanning this disk for recoverable files.

Recover data from unreadable disk on Mac

3. After the scanning process finishes, you can click the found files and preview.

4. Choose what you want to get back and click "Recover".

Step 2: Initialize the unreadable disk.

1. Unplug the unreadable disk and then plug in again.

2. Click Initialize button when the error message appears.

3. Follow the instructions to finish the initialization process.

In this way, you can successfully fix the disk is unreadable error on your Mac without any data loss. What's more, if you mistakenly clicked on the Initialize button without any backup, you can also try out iBoysoft Mac Data Recovery because it's able to recover files from formatted drives.

Still have questions?