How to Fix '' Error on an External Hard Drive

This post will introduce how to fix the '' errors on a Mac disk, including external and internal hard drives. Install EaseUS Data Recovery Wizard for Mac to recover your lost data in case permanent data loss!

Table of Contents

When you go to Disk Utility to check the external hard drive you connected that is grayed out and click the "Mount" button to mount it manually, you may receive the error message like "Couldn't mount 'disk name'. ( error)". It's an unmounting error that prevents you from accessing stored data on the drive.

The most common "" errors are as follows:

What does the " error" mean, and can you fix it without losing data? This post will discuss the effective solutions for the common unmountable error codes:

The first five methods can solve the "DiskManagement.disenter" errors without damaging data; however, if these five fixes don't work, consider using Fix 6, the most effective and fastest solution, reformatting your hard drive, which is accompanied by data loss.


Backing up your hard disk data and formatting it directly is the most effective and hassle-free solution to these "" errors. However, if you don't have any important data on your hard disk, consider formatting it directly.

Back Up Your Mac and Never Lose Data

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What Are DiskManagement Disenter Errors & Possible Causes

The " error" occurs when you mount a disk on a Mac by clicking the "Mount" button in Disk Utility. This error indicates there's a mounting error between your Mac and hard drive, including:

Mac Issues:

  1. ❌Incompatible software installations
  2. 😰System bugs after updating
  3. ⛔Improper permissions and security settings
  4. ⚠️FSCK program is stuck in the checking process

Hard Drive Errors:

  1. 📁Corrupted file system and directories
  2. ❎Incompatible file system with macOS
  3. 🔌Not ejected properly last time
  4. 💾Insufficient storage space

Referring to the possible causes above, it's clear that the problem doesn't always result in data loss. However, if the stored data is essential, EaseUS Data Recovery Wizard for Mac is on standby to rescue your data, keeping you away from losing data.


You Can Trust EaseUS Data Recovery Software

EaseUS Data Recovery Wizard has acquired an extensive technical base in data recovery and trusted by billions of users since 2005. Check out reviews on Trustpilot.

Utilize this handy data recovery software to recover an unmounted external hard drive on a Mac with only 3 steps!

Step 1. Select the unmountable hard drive and click "Search for lost files" to find all recoverable files.

Step 1. Search for lost files

Step 2. Select the file type to find the files you want on your unmountable hard drive.

Step 2. Filter and find lost files

Step 3. Click the file and preview it. Then, select the files you want to recover and click "Recover".

After saving your important files on the unmountable hard drive, check the following 6 solutions to fix the " error".

Share this article on social media to help others learn what the " error" is and how to solve it in 6 ways.


Fix 1. Check Connection Issues

Ensuring a secure physical connection for your external hard drive is vital for smooth mounting. To check the USB cable or port, connect it using a different cable or insert it into an alternative USB port on your Mac. This fix aids in resolving the " error" if it results from connectivity issues.

Fix 2. Restart Your Mac

The unmountable hard drive errors could be due to a temporary bug in macOS. Restarting your Mac is a simple solution to refresh the operating system and remove temporary system glitches: click on the Apple icon and select "Restart" from the drop-down menu.

Restart Your Mac

Fix 3. Run First Aid in Disk Utility

Mac First Aid allows users to repair disk errors with one click. Here's how to repair the unmountable hard drive to solve the DiskManagement disenter error:

Step 1. Open "Disk Utility" and select the external drive in the left panel.

open Disk Utility

Step 2. Click "First Aid > Run" and wait for the process to finish.

run First Aid

If the First Aid process fails, and you still can't access stored data on the unmountable hard drive, install the EaseUS hard drive recovery tool on your Mac and save your files ASAP to avoid permanent data loss.

Fix 4. Repair the Unmountable Error via the Terminal

You can manually mount a disk on a Mac via a command in the Terminal app:

Step 1. Launch Terminal from the "Finder > Applications > Utilities" folder.


Step 2. Type the command diskutil list to find the disk identifier of your unmountable disk.

diskutil list command

Step 2. Enter the command diskutil mount /dev/disk1s2, and replace the "disk1s2" with the unmountable disk identifier.

Fix 5. Stop the FSCK Process

If the DiskManagement disenter error is caused by the incorrect ejecting of the external hard drive, killing the FSCK process may solve this error. Open the "Terminal" app and enter the command line sudo pkill -f fsck, which can stop the FSCK process. Or, you can quit the FSCK process via Activity Monitor:

Step 1. Navigate to "Finder > Applications > Utilities > Activity Monitor".

Activity Monitor

Step 2. Find the FSCK process in the Activity Monitor window, and hit the "Quit" button to stop it.

Fix 6. Reformat the Problematic Disk

The most effective option to solve the " error" issue is to format the hard drive. If the methods we mentioned above are unsuitable for your situation, consider using EaseUS Data Recovery Wizard for Mac to recover the stored data from an uncountable drive and then reformat it.

Here are the steps:

Step 1. Open "Disk Utility" and find the uncountable hard drive. If the external hard drive is not showing up on a Mac, click "Show All Devices".

show all devices

Step 2. Choose the unmounted hard drive, and click the "Erase" button at the top menu.

Step 3. Select any macOS-compatible file system format to the formatted hard drive, and click "Erase" to start the formatting process.

erase a disk on a Mac

Final Words

Suppose the DiskManagement disenter error occurs when you try to mount a disk on your Mac; you can fix it with 6 effective methods, including checking connection issues, restarting your Mac to fix small system glitches, repairing the unmountable disk using the First Aid feature, mounting it via the Terminal app, stopping the fsck process, and reformatting the disk.

To avoid data loss, install the professional and trusted hard drive recovery software EaseUS Data Recovery Wizard for Mac, which can both back up and recover your data in clicks. error FAQs

Here are questions people frequently ask when they search for how to fix the " error" on a Mac. Take a look:

1. Why can't I unmount my hard drive Mac?

"Couldn't unmount disk" errors usually appear in Disk Utility when the boot drive is busy, such as Couldn't Unmount Disk 69888. You should close all open files and programs, reboot the computer, and try again.

2. How do I fix a corrupted external hard drive without formatting it on a Mac?

You can utilize the First Aid tool in Disk Utility:

Step 1. Open "Disk Utility" and click "View > Show All Devices".

Step 2. Select the corrupted volume, then click "First Aid" at the top menu.

Step 3. Hit the "Run" button to confirm the process. When it finished, click "Done".

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Updated by Brithny

Brithny is a technology enthusiast, aiming to make readers' tech lives easy and enjoyable. She loves exploring new technologies and writing technical how-to tips. In her spare time, she loves sharing things about her game experience on Facebook or Twitter.

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