Few things are more frustrating for Mac users than seeing the message: “App is damaged and can’t be opened.” Whether it appears after downloading new software or launching an old favorite, this warning can suddenly block productivity and raise concerns about security. In 2026, macOS security is more advanced than ever, but that also means stricter app verification processes. Fortunately, in most cases, the issue is fixable without advanced technical skills.

TLDR: The “App is damaged and can’t be opened” error on Mac is usually caused by Gatekeeper restrictions, corrupted downloads, permission conflicts, or outdated certificates. Most users can resolve it by re-downloading the app, removing the quarantine attribute, adjusting security settings, or running basic disk checks. In more stubborn cases, resetting permissions or temporarily disabling Gatekeeper restores functionality. These six proven fixes help users safely launch blocked apps in 2026.

Why This Error Happens on macOS

Apple’s security framework, including Gatekeeper, System Integrity Protection (SIP), and advanced app notarization requirements, protects users from malicious software. When an app fails security checks or appears incomplete, macOS blocks it with the “damaged” warning.

Common causes include:

• Incomplete or corrupted download files
• Outdated or revoked developer certificates
• Gatekeeper quarantine flags
• Permission mismatches
• System cache conflicts
• macOS version incompatibility

Understanding the cause makes it easier to apply the correct fix.

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Fix 1: Delete and Re-download the App

The simplest solution is often the most effective. A corrupted or partially downloaded installation file frequently triggers the “damaged” warning.

Users should:

1. Delete the app from the Applications folder.
2. Empty the Trash.
3. Download the app again from the official developer website or Mac App Store.

Important: Avoid third-party download platforms whenever possible. In 2026, macOS notarization requirements are stricter, and unofficial mirrors can cause signature mismatches.

If the error disappears after reinstalling, the issue was most likely download corruption.

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Fix 2: Remove the Quarantine Attribute via Terminal

When apps are downloaded outside the App Store, macOS attaches a quarantine attribute. Sometimes, the system misidentifies safe apps as damaged.

Advanced users can remove this flag through Terminal:

1. Open Terminal (Applications → Utilities → Terminal).
2. Type the following command:

sudo xattr -rd com.apple.quarantine /Applications/AppName.app

Replace AppName with the actual app name.

After pressing Enter and entering the administrator password, macOS removes the quarantine attribute, allowing the system to reassess the app.

Security note: Users should only do this if they trust the app source.

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Fix 3: Override Gatekeeper in System Settings

In some cases, macOS blocks apps due to unidentified developer status—even when they are safe.

To manually override:

1. Open System Settings.
2. Navigate to Privacy & Security.
3. Scroll to the Security section.
4. If the blocked app appears, click Open Anyway.

macOS will prompt confirmation before allowing it to launch.

This method works particularly well for independent developer tools and older software updated for macOS 2026 compatibility.

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Fix 4: Check Disk Utility for Drive Errors

If multiple apps trigger the error, the issue may not be the app—it could be the disk.

Users can run First Aid in Disk Utility:

1. Open Disk Utility.
2. Select the startup disk.
3. Click First Aid.
4. Confirm and allow the scan to complete.

Disk permission corruption or minor file structure issues can interfere with app verification. First Aid repairs these errors automatically in most situations.

This step is especially useful after:

• Unexpected shutdowns
• System crashes
• Failed macOS updates

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Fix 5: Reinstall the App Using Rosetta (For Apple Silicon Macs)

Even in 2026, some applications run via Rosetta translation on Apple Silicon Macs. If a legacy Intel-based app isn’t optimized, macOS may interpret compatibility issues as app damage.

Users can:

• Right-click the app.
• Select Get Info.
• Check Open using Rosetta (if available).

If Rosetta isn’t installed, macOS will prompt installation automatically when launching an Intel-only app.

Alternatively, users should check the developer’s website for Apple Silicon-native versions, as most actively maintained software now supports ARM architecture.

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Fix 6: Temporarily Disable Gatekeeper (Advanced)

If none of the previous methods work, temporarily disabling Gatekeeper can help determine whether macOS security enforcement is causing the issue.

Using Terminal:

sudo spctl --master-disable

This enables the “Anywhere” option under allowed apps.

After launching the application successfully, users should re-enable Gatekeeper:

sudo spctl --master-enable

Important: This should only be done temporarily and with trusted software. Disabling system security permanently increases vulnerability.

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Additional Troubleshooting Tips

Check macOS Compatibility

Some apps labeled as “damaged” are actually incompatible with the latest macOS version. Developers sometimes discontinue older software without updating certificates.

Restart the Mac

System glitches, cache conflicts, or temporary verification failures may resolve after a full restart.

Clear Extended Attributes

Beyond quarantine flags, other extended attributes can interfere. The xattr command can display all metadata attached to a file.

Create a New User Account

User-profile-specific corruption may be the culprit. Testing the app in a new user account helps isolate permission issues.

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When the Error Signals Real Malware

While most “damaged” warnings are false positives, occasionally macOS blocks apps for legitimate threats.

Red flags include:

• The app comes from an unknown or unofficial website
• The developer cannot be verified
• System prompts appear repeatedly after deletion
• The app requests excessive system permissions

In 2026, Apple’s XProtect and Malware Removal Tool operate automatically in the background. Users should allow macOS to block suspicious applications rather than overriding security blindly.

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Preventing Future App Damage Errors

Prevention remains easier than troubleshooting. Mac users can reduce errors by:

• Downloading software only from reputable sources
• Keeping macOS updated
• Avoiding forced shutdowns
• Using stable internet connections for downloads
• Regularly running Disk Utility First Aid

Developers have improved certificate management in 2026, yet system-level verification is stricter. Taking preventive measures ensures smoother app performance long term.

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FAQ

1. Why does macOS say an app is damaged even if it worked before?

Certificate expiration, revoked developer signatures, or macOS updates can cause previously working apps to fail verification checks.

2. Is it safe to use Terminal to bypass the error?

Yes, if the app comes from a trusted source. Users should avoid bypassing security for unknown or suspicious software.

3. Does this error mean the app contains a virus?

Not necessarily. In most cases, the problem relates to security verification or file corruption rather than malware.

4. Can antivirus software fix this issue?

Usually not. The message originates from macOS security mechanisms, not third-party antivirus programs.

5. Why does the error appear after updating macOS?

Major updates introduce updated security rules and stricter notarization checks. Older apps may fail these new requirements.

6. Should Gatekeeper remain disabled?

No. Gatekeeper should only be disabled temporarily for troubleshooting and reactivated immediately afterward.

7. What if none of these fixes work?

If all solutions fail, reinstalling macOS (without deleting personal data) may resolve deeper system-level corruption.

By following these six targeted fixes, most Mac users in 2026 can restore blocked apps quickly and safely. While Apple’s evolving security measures sometimes create inconvenience, they also protect against increasingly sophisticated threats—making careful troubleshooting well worth the effort.