How to Fix "App Is Damaged and Can't Be Opened" on Mac (2026 Guide)

Why macOS Says the App Is "Damaged" (It Usually Isn't)

If you just downloaded an app — often from a developer's website rather than the Mac App Store — and macOS pops up a dialog saying "[App Name] is damaged and can't be opened. You should move it to the Trash", don't panic and don't delete it just yet. In the vast majority of cases, the app isn't actually corrupted at all.

This message is macOS's Gatekeeper security system reacting to one of a few things:

• The app isn't notarized by Apple (the developer didn't submit it for Apple's automated malware scan).
• The download picked up a quarantine attribute (com.apple.quarantine) that got flagged incorrectly, often because the file was unzipped by a third-party archive tool or transferred via a method that stripped the original code signature.
• The code signing certificate is invalid, expired, or was revoked after the app was built.
• You're on a newer macOS version (Sequoia, or the newer macOS Tahoe) with stricter Gatekeeper enforcement than the version the app was originally tested on.

Apple worded this dialog vaguely for security reasons, but "damaged" here almost always means "untrusted," not "broken." The fixes below range from the safest, most targeted method to a more advanced last resort — work through them in order.

Quick Fix: Remove the Quarantine Attribute via Terminal

This is the fastest and safest fix for most users, and it's the one we recommend trying first. It simply removes the quarantine flag macOS attached to the file, without disabling any system-wide security feature.

1. Open Finder, drag the affected app into your Applications folder if it isn't there already.
2. Open Terminal (Applications > Utilities > Terminal, or search via Spotlight).
3. Run the following command, replacing AppName with the actual app name:

xattr -cr /Applications/AppName.app

The -c flag clears all extended attributes and -r makes it recursive, covering every file inside the app bundle. Press Enter, type your admin password if prompted, and try opening the app again.

If you're not sure of the exact folder path, you can drag the app icon directly into the Terminal window after typing xattr -cr (with a trailing space) — Terminal will auto-fill the correct path for you.

For most downloaded utilities, this one command resolves the issue completely, because it removes the specific attribute Gatekeeper was reacting to while leaving every other security check active.

Method 2: Re-download and Reinstall the App

If the quarantine removal didn't help, the download itself may genuinely be incomplete or corrupted — especially if it came through an unreliable connection, a torrent, or a mirror site.

1. Delete the current copy of the app from Applications (drag it to Trash, then empty the Trash).
2. Go back to the official developer website or the Mac App Store and download a fresh copy. Avoid third-party download aggregators, which sometimes repackage installers and strip or corrupt code signatures.
3. If you downloaded a .zip file, let macOS's built-in Archive Utility handle the extraction (double-click it) rather than a third-party unzip tool, some of which mishandle extended attributes.
4. Install the fresh copy and try opening it.

This also rules out a genuinely damaged download, since re-downloading gives you a clean, correctly signed copy of the installer.

Method 3: Allow the App via System Settings > Privacy & Security

On modern macOS versions (Sonoma, Sequoia, and macOS Tahoe), Apple moved the override option into System Settings instead of a simple right-click "Open" as in older versions.

1. Try opening the app once (even though it will show the damaged/blocked warning) — this registers the block event with macOS.
2. Go to System Settings > Privacy & Security.
3. Scroll down to the Security section near the bottom of the page. You should see a message like: "[App Name] was blocked to protect your Mac."
4. Click Open Anyway.
5. You may be prompted for your admin password or Touch ID. Confirm, and then try opening the app again from Launchpad or Applications — you'll get one more confirmation dialog with an Open button.

This is Apple's officially supported way to override Gatekeeper for a specific app you trust, without weakening security for anything else on your Mac.

Method 4: Temporarily Disable Gatekeeper (Advanced)

Use this method only as a last resort, and only for apps from a source you fully trust. Disabling Gatekeeper system-wide removes a core layer of malware protection for every app you install while it's off.

1. Open Terminal and run:

sudo spctl --master-disable

2. Enter your admin password when prompted.
3. Go to System Settings > Privacy & Security and confirm that "Allow applications from" now shows an Anywhere option, and select it.
4. Open the app that was previously blocked.
5. Immediately re-enable Gatekeeper by running:

sudo spctl --master-enable

Leaving Gatekeeper permanently disabled exposes your Mac to unsigned and potentially malicious software with no automatic vetting. Treat this as a brief, targeted exception — not a permanent setting — and re-enable it as soon as the app has opened successfully.

If you're regularly running into "damaged app" errors across multiple machines, or you're not comfortable running Terminal commands, it's worth getting a professional to check your Mac's security settings and app sources rather than repeatedly disabling Gatekeeper. Our team offers one-off remote Mac troubleshooting support if you'd rather have an expert resolve it safely in a single session.

Frequently Asked Questions

Is my Mac actually infected if it shows the "app is damaged" message?

No. This message is Gatekeeper's response to an untrusted or unnotarized code signature, not a virus scan result. It appears even for completely legitimate, safe apps that simply weren't notarized by Apple or lost their signature during download.

Why does this happen more often on macOS Tahoe?

Apple has progressively tightened notarization and code-signing requirements with each macOS release. macOS Tahoe enforces these checks more strictly than older versions, so older or less actively maintained apps are more likely to trigger the warning.

Will removing the quarantine attribute make my Mac less secure?

Removing it only affects the specific file or app you target with xattr -cr. It does not disable Gatekeeper, System Integrity Protection, or any other macOS security feature, so your overall system protection stays intact.

What if the app still won't open after trying all four methods?

At that point the installer file itself may be genuinely corrupted, incompatible with your macOS version, or built for a different processor architecture (Intel vs. Apple Silicon). Check the developer's system requirements and consider reaching out to their support directly.

Can I avoid this error altogether in the future?

Download apps only from the Mac App Store or directly from verified developer websites, avoid third-party "free download" aggregator sites, and let macOS's built-in Archive Utility handle unzipping instead of alternative unzip tools.