Force Quit any crashing Mac apps by right-clicking the icon in the dock then holding the Option key and selecting "Force Quit" from the menu. You can also locate and quit apps that aren't responding with Activity Monitor, restart your Mac, install outstanding updates, and completely delete and reinstall the app.

macOS is a stable and productive operating system that, assuming you have enough free space and RAM available, should just keep on trucking. This isn’t always the case with third-party apps, which on a Mac are often more likely to stop responding than the operating system itself.

Force Quit Hung or Frozen Apps

If an app has crashed and is not responding, failed to properly launch, or the icon is bouncing around in the dock with seemingly nothing happening, you can always use Force Quit to end the process.

To do this, right-click on the app’s icon in the dock then hold the Option key on your keyboard and choose “Force Quit” from the context menu. The app should immediately close and you can try opening it again.

Locate and Quit Problem Apps with Activity Monitor

Sometimes problem apps can cause your Mac to slow down, become sluggish, or throw the perpetual spinning wheel of death. Normally if an app has become unresponsive you can still Command+Tab between other apps, but performance may be noticeably affected.

This is particularly the case if the app in question is hogging resources like processing power and RAM. That’s where Activity Monitor comes in. This built-in utility allows you to spot problems and kill the cause in just a few clicks.

macOS Activity Monitor

Launch Activity Monitor either by triggering Spotlight (Command+Spacebar) and then searching for it or by finding it under Applications > Utilities. Now use the CPU and Memory tabs to sort the “% CPU” and “Memory” tabs in descending order, with the apps using the most resources at the top.

If you notice a problem app sitting at the top using a huge amount of CPU (over 100%, for example) or squatting a large amount of memory then you can click on it, then click on the “X” button at the top of the window to kill the process.

Also, be on the lookout for any apps highlighted in red or that have the “(Not responding)” suffix after the app name.

RELATED: How to Monitor CPU Usage on Your Mac's Dock

Restart Your Mac

Sometimes restarting all of the processes that an app may depend on is the best solution to the problem. To do this, restart macOS by clicking on the Apple logo and choosing “Restart” then confirming your decision.

Restart macOS without reopening applications on login

Try Updating the App

It can be hard to update an app that won’t launch, since many macOS apps depend on auto-updaters built into the app itself. That’s not the case for all apps, however, like those installed via the Mac App Store. You can update these apps by launching the Mac App Store then clicking on the “Updates” option in the sidebar and clicking “Update” next to the app in question.

Update apps in Mac App Store

Some apps have separate updaters, including suites like the Adobe Creative Cloud and games installed through storefronts like Steam. Update these by launching the companion app and scanning for updates.

If the problem app was installed using the Homebrew package manager, open Terminal and run the brew upgrade command, or target the app specifically with brew upgrade <name>.

Delete and Reinstall the App

You can also try deleting problematic and crashing apps and then reinstalling them again, preferably with a more up-to-date and reliable version. To do this, open the Applications folder in Finder and find the app that’s causing an issue. Right-click on it and choose “Move to Bin” or drag the app from the Applications folder to the Trash in your dock.

Delete an application in macOS with Finder

Now launch Finder and click Go > Go to Folder and type or paste ~/Library/Preferences and delete any app preferences files left over for the app you just deleted.

You can also perform a thorough uninstallation with an app like AppCleaner, which scours your drive for any traces of the app and attempts to remove them. Finally, restart your Mac and reinstall the app to try again. We recommend first trying the very latest version, before considering older (potentially more stable) versions if you’re still having trouble.

Remove App Plugins or Modifications

Sometimes additional software may cause an app to crash or not respond. This could be a plugin or a modification that you’ve installed for use with the app that’s causing the issue. Some examples include brushes or filter plugins in photo editors, VSTs and AU modules in music production environments, and modifications or custom items in games.

An affected app may scan a designated folder and attempt to load plugins on launch. This could cause the app to crash or hang, so removing these plugins and trying again is worth a shot (especially if the problem started after you installed an optional extra).

We recommend adding back plugins or modifications one by one until you find the source of the problem, rather than replicating the exact circumstances that led to the problem in the first place.

What to Do If an App Won’t Launch at All

If an app just hangs and then doesn’t do anything, and you’ve tried every solution above, there’s a good chance that it’s simply broken. There isn’t much else you can try to solve the issue, so searching for an alternative to this app using a website like AlternativeTo is your best bet.

If you see a  “developer cannot be verified error” you can override this security measure and open the app anyway. This happens when the app isn’t signed with a valid Apple Developer certificate, a measure Apple uses to inspire a degree of trust in third-party apps. If you trust the app, head to System Settings > Privacy & Security and click on the “Open Anyway” button to open the app

If you see the app “is damaged and can’t be opened” then there’s a good chance it’s been caught in quarantine. This happens when macOS suspects that an app is dangerous, but many innocuous apps get caught in the net.

File is Damaged Error on macOS

If you trust the source of the download (like a developer’s website), you can go ahead and open it. Try right-clicking it and selecting “Open” or use the xattr command in Terminal to whitelist the app.

Could macOS Be to Blame?

Some Intel Mac apps may lack universal binaries which causes problems with Apple Silicon models due to Rosetta 2 incompatibilities. You can confirm this by checking the app “Kind” under System Information > Software > Applications (find this option by clicking Apple then holding Option and choosing System Information).

Check application "Kind" in System Information on macOS

Some apps simply don’t work properly after an upgrade to a new version of macOS. You can always grab and install an older version of macOS if you depend on an app that no longer works and want to roll back.

Still got problems? Learn how to diagnose and fix a slow or unresponsive Mac, as well as the warning signs to look out for that signal your Mac may have a problem.

Profile Photo for Tim Brookes Tim Brookes
Tim Brookes is a technology writer with more than a decade of experience. He has covered a wide range of topics including Apple, security, productivity tips, gaming and more for publications like How-To Geek, Zapier, and MakeUseOf.
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