Get rid of 'The following disk images couldn't be opened” warning

The Mac system is easy to use and powerful, but sometimes you may need to download applications or other tools from independent developers that are not available in the App Store for some reason. In this case, the application may be provided in the form of a compressed disk image. This works perfectly for the most part. But sometimes, you may see the error message "Cannot open the following disk image". The most common reasons are as follows: the disk image file is corrupt, the disk image is unrecognized, or there is no file system to install. If you want to know how to fix this error, this guide is for you.

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Free Trial What is a Disk Image?

Mac uses a unique image file format called Disk Image (dmg) to emulate physical disks. It has the same functionality as a physical drive, so you can install it in Finder, transfer files and folders to it, create clones of it, and burn it to a physical medium such as a CD, DVD, or memory stick. They are extracted in the same way as normal disks. Disk Utility allows you to browse through it and even create your own disk image.

Earlier, disk images were used to distribute applications remotely on a Mac. However, with the release of macOS X, they are outdated. On the other hand, they are still a popular choice for Mac software distribution. This is mainly because they allow developers to control how the software is rendered when the image is opened. For example, if you have ever downloaded an application that prompts you to put the binary of the application into the "Applications" folder, along with the alias of the folder, you must use a disk image to achieve this.

As an exact copy of the source device containing the files and structures of the original storage media, disk images can also be used to create system backups and data recovery.

Now that you know how to answer “What is a Mac disk image?” and that you might encounter it while using a Mac, let’s finally take a closer look at the warnings you may face.

Troubleshooting "Cannot open the following disk image"

If you try to boot the disk image on your Mac but receive a warning message similar to the disk image that cannot be opened, consider using the following methods to resolve the issue.

Re-download disk image

If the disk image is corrupted, the disk image file cannot be opened. Corruption can occur during the download process due to network instability, malware attacks, or other interference. So, you need to check your network before re-downloading the disk image. Once you have obtained the file, double-click it to see if it can be started now.

Tip: Control the download speed. Files are downloaded from the internet as a single stream, which takes some time and megabytes. With Folx Pro, this stream can be divided into up to 20 smaller streams, each completing much faster. Therefore, your overall download speed will be 20 times faster.

Verify disk image using Disk Utility

Unfortunately, even if you re-download the disk image over a stable network, you may still "cannot open the following disk image" when you try to open the disk image. In this case, you should consider whether there is a problem with your Mac with disk image installer. To verify the disk image, use Disk Utility. Here are the steps to follow:

1. In Finder, click Go to > Utilities > Disk Utility
2. Click "Image" in the menu bar and select "Verify"
3. Find the disk image file (usually the "Download" folder) in the folder where it is stored. Click Verify
4. After the verification process is complete, click Finish.

Open the disk image after verification is successful. Mac image is unrecognized again? Try the next solution.

Tip: There are a number of ways you can create disk images on your Mac. One of the easiest ways is to use Disk Drill. The method is as follows:

1. Open Disk Drill – You can download it through Setapp
2. Select "Bytebyte DMG Backup" from the left sidebar
3. Select the source drive or partition
4. Then click Create Backup
5. Select the location where you want to store the disk image
6. Finally, click Save to create the image.

Run maintenance scripts

When the disk image fails to open, it may be a problem with your Mac rather than the disk image itself. On your boot drive, files accumulated over time can cause conflicts and prevent the opening of the disk image or the normal operation of the software. Fortunately, the CleanMyMac X application can help solve these problems. It can run system optimization maintenance scripts, repair disk permissions, and free RAM. Here are the actions you need to do:

1. Install CleanMyMac X – You can download it through Setapp
2. Then open the application and click Maintenance in the left sidebar
3. Select Run maintenance script and click Run.

As we mentioned, running maintenance scripts can fix many errors. So hopefully once the process is complete, you will find that the "disk image cannot be opened" issue has been resolved.

Disk image cannot be installed

What if my disk image cannot be installed? Download the Disk Drill Data Recovery application.

With its help, you can create Mac disk images (dmgs) from any media (disks, memory cards, etc.). This is very useful for future recovery, especially if the disk you need to use fails.

If the disk image cannot be installed (viewed) on your Mac or you receive a "No file system to install" warning, you can try attaching a non-installable disk image using Disk Drill. The method is as follows:

1. Select Attach an Uninstallable Image from the File menu in Disk Drill
2. Then select the disk image file by navigating to its location and clicking Attach. That's it!

"Cannot open the following disk image" resolved

When opening a disk image on a Mac, you may sometimes see an error like "Cannot open the following disk image". If this happens, consider the suggestions in this article to resolve this issue. While one of the most effective ways is to re-download the disk image (you can use Folx to increase download speed), in this case, running maintenance scripts with CleanMyMac X will not cause any harm. Most importantly, if the disk image cannot be installed (viewed) on your Mac, we recommend that you use Disk Drill. All three apps can be downloaded from Setapp, a premium platform that can unlock access to multiple Mac and iPhone tools (240 and above) for a small fee, meeting the various needs of Apple users. The best part: All apps are free to try for 7 days, with no ads and complicated operations.

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