Application Can’t Be Opened on Mac: How to Fix It

If your Mac says an application “can’t be opened,” the cause may be a damaged download, an app macOS cannot verify, a permissions issue, or an outdated app. Work through these checks in order, starting with the safest options; you’ll need an internet connection for updates or a fresh download.

What You’ll Need

Your Mac’s administrator password, if macOS asks for it.
An internet connection to check for app or macOS updates, or download the app again.
The app’s original, trusted download source. Avoid third-party download sites.

Step-by-Step

Read the full alert. Note whether it says the app is damaged, cannot be verified, is from an unidentified developer, or is not supported on this Mac. These messages point to different causes. Don’t bypass a warning before confirming that you trust the app and its source.
Quit and try again. Click Cancel or OK in the alert, then open the app from the Applications folder. If it appears to be stuck, press Option-Command-Escape, select the app in the Force Quit window, and click Force Quit. Restart your Mac from the Apple menu and try once more.
Check compatibility. Find the app’s requirements on its developer’s official website or in its trusted store listing. Confirm that your macOS version and Mac type are supported. To check your Mac, open the Apple menu and choose About This Mac. If the app needs a newer macOS version, use System Settings > General > Software Update to check for a compatible update, if one is offered. Otherwise, ask the developer for a supported version.
Update the app or download it again. If you installed it through the App Store, open the App Store and check Updates. For other apps, use the developer’s official update instructions. If the download may be incomplete or macOS says it is damaged, delete the app and download a fresh copy from the original trusted source. Follow the developer’s instructions for uninstalling; some apps store documents or settings separately, so don’t delete those without checking.
Try the normal first-open exception for a trusted app. If the alert says the developer cannot be verified, confirm that you intentionally downloaded the app from its developer or another source you trust. Open System Settings > Privacy & Security and scroll to the Security section. If macOS shows an option to open the blocked app, select it and confirm. This option may appear only after you have tried to open the app once. Menu wording and layout can differ across macOS versions.
Use Open from the app’s Finder menu if appropriate. For an app you trust that macOS identifies as being from an unidentified developer, locate it in Finder, Control-click (or right-click) it, and choose Open. Review the warning and choose Open only if you are certain the app is legitimate. This is a deliberate exception for that app, not a reason to disable macOS security protections globally.
Check whether the app is allowed to open. In Finder, select the app and choose File > Get Info. If the file is marked as locked, close the app, select the Locked checkbox to clear it, then try opening it. If you see a Sharing & Permissions section, make sure your account has permission to read and execute the app. Change permissions only if you understand the setting; don’t set broad access for everyone as a shortcut.
Test a fresh download before changing anything else. If the app still fails, remove only the app itself using the developer’s instructions, restart the Mac, and reinstall it. Don’t run Terminal commands, remove security attributes, or turn off Gatekeeper based on a random online fix. Those steps can expose your Mac to untrusted software or damage app files.

Common Mistakes

Choosing “Open Anyway” without checking the source. An alert can be an important warning. Proceed only when you deliberately obtained the app from a source you trust and have checked that the download is genuine.
Assuming every “can’t be opened” message means the same thing. A compatibility error, damaged download, and verification warning need different fixes. Use the exact wording to choose the next step.
Deleting support files or app data at random. Documents, preferences, and libraries may be stored outside the app. Back up important files and follow the developer’s uninstall guidance.
Changing permissions broadly or disabling security. Giving every user full access or turning off built-in protections can create risks without fixing the underlying problem.

Tips

Keep a note of the exact alert text and where you downloaded the app; this helps the developer identify the issue.
Prefer the App Store or the developer’s official website, and avoid opening unexpected app downloads from email attachments or pop-ups.
After updating macOS, check the app developer’s compatibility information before reinstalling an older app.
If you use a work- or school-managed Mac, contact its administrator before changing security settings. Management policies may block app installation or opening.

Troubleshooting

The message says the app is damaged. Don’t try to force it open. Delete the app and download it again from its original trusted source. If the fresh copy is still flagged, stop and contact the developer; the app may need an updated or correctly signed release.

The message says the developer cannot be verified. Confirm the app’s source and check for a newer version. If it is an app you knowingly downloaded and trust, use the per-app exception in Privacy & Security or Finder’s Control-click > Open option. If you cannot establish that the app is legitimate, leave it closed.

The app is greyed out or says it is unsupported. Check the developer’s system requirements and whether a version for your Mac and macOS is available. A security exception will not make an incompatible app work.

The app opens and immediately quits. Restart the Mac, install available app updates, and check the developer’s support instructions. If the same problem continues, note when it happens and contact the developer. Avoid deleting system files or using cleanup tools to guess at a fix.

You cannot see an “Open Anyway” option. First try opening the app once, then check System Settings > Privacy & Security again. If the option still does not appear, your macOS version, the alert type, or a management policy may not offer it. Don’t disable protections to make the option appear.

Frequently Asked Questions

Why does my Mac say an application can’t be opened?
Common causes include an incomplete or damaged download, an app that is incompatible with your Mac, a permissions problem, or macOS being unable to verify its developer.

Is it safe to click “Open Anyway”?
Only if you trust the app and have confirmed its source. If the download was unexpected or you cannot verify it, cancel and remove it.

How do I open an app from an unidentified developer?
After trying to open it, check System Settings > Privacy & Security for a per-app option, or Control-click the app in Finder and choose Open. Proceed only if you trust the app.

Will reinstalling the app delete my files?
It depends on the app. Some keep user documents and settings separately, while others may remove associated data during uninstall. Check the developer’s instructions and back up important files first.

What if the app still will not open after these steps?
Check compatibility, record the exact error, and contact the app developer. If the Mac is managed by work or school, ask its administrator before changing settings.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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