A common issue that usually occurs on Mac OS X and MacOS High Sierra operating systems is that the system does not accept the external drive when it is connected to it. The error message that generally appears is this: "the disk you inserted was not readable by this computer". Fortunately, there are solutions available.
There could be a number of reasons behind the occurrence of this error. Following are some common scenarios that could trigger this issue:
Disk Failure: If the external drive that you are trying to connect has failed, the operating system is likely to show the disk not readable error.
The Disk is Unformatted: If the external drive that you connected to your computer is not formatted, then the chances are high that you will see this error.
WD Software Bug: The issue of drive not being readable might occur with WD hard drives. This generally occurs due to a race condition on 1394 bus that corrupts the table of contents of the VCD.
If you encounter the drive not readable error, then it is highly recommended that you try to fix it with Disk Utility. This is because several users have reported that they were able to promptly fix the problem via Disk Utility. Follow these instructions:
Step 1. When you see the error message upon connecting the USB drive, click Ignore to dismiss it.
Step 2. Now launch Disk Utility via the Launchpad on your Mac.
Step 3. Once it is launched, select the USB drive and click on the First Aid button. Now wait for the process to complete. If the repair is successful, the Disk Utility will notify you.
You won't see "The disk you inserted was not readable by this computer" issue again on your Mac after initializing the unreadable device. But keep in mind that it will erase all the data stored on it. So, it is suggested that you use a professional data recovery tool i.e. iMyFone AnyRecover to recover your important data from it before initializing it.
AnyRecover for Mac is a reliable data recovery tool with a user-friendly interface. You can use this tool to quickly and easily recover your desired data from the external storage device even when it is unreadable.
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Allows you to preview the recoverable data so that you can restore them selectively.
Recover Data from External Device
1. Connect your external drive to your Mac and open AnyRecover. Select External Device Recovery.
2. Next, select the type of your external device and click on the Next button to continue.
3. Now choose the types of files that you wish to recover and then click on the Scan button. The scanning process will begin.
4. Once the scanning is complete, preview and select the desired recoverable files and recover them via the Recover button.
Now that you have recovered your desired data from the USB flash drive via AnyRecover, you can proceed to initialize the external drive via the Disk Utility. Follow these instructions:
1. Launch Disk Utility on your Mac.
2. In the left sidebar, find and select the unreadable external drive.
3. Click the Erase tab and input the related info.
4. Now click on the Erase button to start the Initializing process. Once the formatting process is completed, the unreadable external drive will be initialized and the operating system will read it correctly.
Now you can copy the data that you recovered via AnyRecover to the external drive.
If the external drive is encrypted via BitLocker, then it is likely that you will see "The disk you inserted was not readable by this computer" error on your Mac. This is because Mac does not support BitLocker so it will simply show the disk as not readable. To solve this issue, you will need to connect your external drive to your Windows PC and turn off the BitLocker encryption so your Mac can read it.
If your external drive has a file system that is unrecognizable by your Mac, then you will see "The disk you inserted was not readable by this computer" error. This is because the file system of the drive is simply not compatible with Mac. You can check the file system of an external drive via Disk Utility's "Info" section.
By Simon Marcus , to External Device Recovery
Posted on Apr 24, 2019 ( Updated: Jun 01, 2020 )