Fix Unable To Expand Zip Error 79 On Mac (2025 Update)

Ever faced the frustrating ‘Unable to Expand Zip File Error 79’ on your Mac? You’re not alone.

This common hiccup can happen when you’re trying to unzip files, hinting at issues like an inappropriate file type or corrupted data.

This article examines the Unable to Expand Zip Mac error 79, explaining why it happens and how you can fix it swiftly. From verifying file integrity to simple software updates—and a handy guide on using SpyHunter for added security—we cover all the bases to get your files opening smoothly again.

What is Mac Error 79?

Mac Zip Error 79, also known as “Unable to Expand Zip File Error 79,” is a common error message Mac users can run into when attempting to extract zip files using the Archive Utility.

This error usually appears with a message indicating the file type or format, which prevents the file from being decompressed correctly.

The problem can stem from various causes, such as corrupted zip files, incomplete downloads, or incompatible software versions. If you want to learn more about Mac error codes, check our detailed guide for additional insights and troubleshooting advice.

What causes Mac Error 79

The primary cause of Mac Error 79 is typically linked to corruption within the compressed file itself or compatibility issues between the Archive Utility and the file’s format.

When the zip file is incomplete or improperly downloaded, it may not expand as expected, triggering this error.

Additionally, if the Archive Utility version isn’t up-to-date or is incompatible with the operating system’s current version, users may encounter difficulties opening zip files, leading to Error 79.

Error 79 is no reason to freak out as it is one of the most common zip errors you will encounter on a Mac computer.

Regular updates of both the operating system and the used applications are recommended to minimize the risk of such errors.

How can you fix Mac Error 79?

Encountering the Mac Zip Error 79 can be frustrating when you’re trying to access files. Luckily, there are several ways to resolve this issue efficiently and effectively.

Let’s walk through some proven methods.

Step 1: Verify the integrity of the zip file

First, ensure the zip file itself is not the source of the problem. This error can occur if the file is incomplete or damaged.

This is often due to interruptions during the download process that can happen on a poor internet connection.

If possible, re-download the file from its original source, ensuring a stable internet connection. If you have access to a checksum or an MD5 hash, use these to verify the file’s integrity.

Step 2: Reset permissions to solve extraction issues

Sometimes, improper file permissions can prevent zip files from expanding. To reset permissions:

Open Terminal from the Applications > Utilities folder.

Type chmod 755 [path/to/your/file.zip] and replace [path/to/your/file.zip] with the actual path to your zip file. Press Return.

This command adjusts the permissions, potentially resolving any access issues related to the zip file.

Step 3: Update your macOS to the latest version

Running an outdated version of macOS can lead to compatibility issues with newer software and file formats, including zip files. Check for any available macOS updates:

Open System Settings from your Dock or Apple Menu and select Software Update.

If an update is available, download and install it following the on-screen instructions. Updating your system can resolve errors caused by system incompatibilities and improve overall performance and stability.

Use SpyHunter to scan for malware and optimize your system

Malware or viruses can often interfere with file operations on your Mac, including expanding zip files.

SpyHunter offers a robust defense mechanism against malware and viruses and can potentially fix Error 79 by removing harmful software.

Here’s how to install SpyHunter and use it to run a malware scan on your Mac:

1. Download the app hereDownload the app here and follow the instructions to install it.
2. Once installed, launch SpyHunter and perform a full system scan to detect and remove any potential threats.

3. Select any malware found and proceed with the automated removal process.

Malware can interfere with the normal operation of your Mac, and having a reliable anti-malware tool like SpyHunter can make a world of difference in staying safe and maintaining a smooth system.

Troubleshooting common issues during ZIP file extraction

Dealing with incomplete downloads

An incomplete download is a common culprit behind zip file extraction issues on Macs.

This problem usually occurs when your internet connection is interrupted during the download process. Abruptly closing your download window can also disrupt the connection, leading to incomplete file recovery.

To address this issue:

1. Ensure a stable internet connection before initiating the download process.
2. Reattempt downloading the zip file, and make sure you do not close the download manager or browser prematurely.

This can be an inconvenience when you are looking at large files inside your downloads folder, but it’s a good solution.

If problems persist, consider using a reliable download manager to help manage and ensure complete retrieval of the file.

Overcoming password protection hurdles

If a zip file download comes with password protection, you need the correct password to access its contents. This security measure can sometimes obstruct access if the password is lost or forgotten.

The only real solution here is to search for the password on the original website or contact the file creator if possible.

If all else fails and you cannot retrieve or guess the password, you might need to obtain a new copy of the zip file or an alternative version that isn’t password-protected.

You simply cannot extract files that are password-protected without the password.

Preventive measures to avoid zip errors in the future

To ensure smooth performance and prevent zip errors on your Mac, implementing certain preventive measures is vital.

By adopting these proactive strategies, you can safeguard your data and minimize disruptions caused by file compression issues.

Regular system scans

Keeping your Mac free of malware and ensuring its healthy functioning is critical in avoiding zip file errors. Regular system scans are a key preventive measure.

SpyHunter offers a robust solution for detecting potential threats that could damage or corrupt your files, including zip files.

SpyHunter, with its advanced scanning technology, can efficiently identify vulnerabilities and threats that might lead to file corruption.

By running periodic scans, you ensure that your system remains secure and any suspicious activities are addressed promptly.

Maintaining updated software

Outdated software can often lead to compatibility issues and other errors, such as problems with expanding zip files.

To prevent such issues, it is crucial to keep your operating system and all installed applications up-to-date.

This involves regularly checking for updates and configuring your Mac to install these updates automatically.

These updates not only enhance security but also improve the overall reliability of your software, reducing the chances of encountering zip errors.

Updating your macOS is a straightforward process:

• Click the Apple menu and then click on System Settings.
• Choose Software Update.
• Click on Upgrade Now to install the latest version.

By ensuring your system and applications are up-to-date, you substantially decrease the likelihood of issues arising from incompatible or outdated software components.