Solve the MacOS Error 'Application Won't Open' as Lightly as a Breeze

How do I fix the frequent "app not opening" error?

There is a common system glitch in MacOS (Sierra, High Sierra) and MacOS X (Yosemite, El Capitan) where a strange error message pops up when users attempt to interact with applications such as Preview, Finder, App Store, Safari, Google Chrome, Xcode, Steam, iTunes, and more. The error reads, "The application xx.app is no longer responding." This issue seems persistent and does not go away permanently, even after multiple restarts.

This is strange, because sometimes the application in question is actually open and displaying on the screen, yet the error persists. Why?

Usually, when you encounter this error, the app becomes unresponsive and you can't quit it normally to restart it. Even if you manage to force it closed, it may not go away entirely – for example, it might still show up in your Dock, or parts of the app may randomly appear on your screen. You'll need to use some advanced methods to terminate the app or process so you can regain access to the app.

To help you navigate the options, we have divided the available solutions into two broad categories.

The easiest way: Download Mac cleaner software to remove common MacOS/Mac OS X errors

CleanGenius is a simple Mac maintenance tool that can help your Mac run faster and better. You can clean your Mac, free up disk space, and speed it up in just minutes. For your case, this super easy-to-use Mac cleaner and optimizer offers an "Uninstall" feature that allows you to uninstall specified apps from here and reinstall them. You can surely give it a try to get rid of the persistent app errors.

Steps to clean your Mac and optimize app performance:

Step 1: Run CleanGenius and click the Uninstall button on the toolbar;

Step 2: Find and select the application, program, or software that you wish to remove, then click Uninstall.
The selected application, program, or software will be removed in a few seconds.

You can also try using the "Quick Clean" feature, another core function of CleanGenius. Sometimes, incorrect configurations upon launching an app can lead to the "app won't open" error.

Additional content: Other methods that individuals can also try

Furthermore, we have other effective fixes for the “Application not opening” error. You can also check out some recommended solutions below.

"Force quit the application"

Step 1. Click the Apple icon in your Mac's menu bar.

Step 2: Choose "Force Quit."

Step 3: The window that appears shows all the apps currently running on your Mac. If the misbehaving app is in the list, select it and click "Force Quit."

Step 4. Restart the app to see if this simple fix worked.

If an app won't open, force it to quit

II. Somewhat Related Processes

Step 1: Open Finder, then go to Applications > Utilities > Activity Monitor. Make sure the "CPU" tab is selected within Activity Monitor.

Step 2: In the “Search” field, type the name of the troublesome app, such as “Safari” or “Preview.”

The Activity Monitor will display all currently running processes that contain the search term. Note that this may include processes unrelated to the app in question, so forcibly quitting everything in this list could have adverse effects on other apps, or even the macOS system as a whole. If your search returns any processes you're unsure about, you can usually find all the information you need online to determine whether it's safe to click the "Force Quit" button.

Step 4: To force an app to quit, click on it, then click the little "X" button (as shown below, where the cursor is).

III. Remove the application's container directory

Step 1: Open a Finder window and choose Go > Go to Folder from the menu bar.

Step 2: Type in the file path: ~/Library/Containers. Then click “Go.”

Step 3: Find the container associated with the troublesome app, such as com.apple.mail for Mail and com.apple.Preview for Preview.

Step 4: If you haven't already, make a copy of this folder and place it outside of the “Library Containers” folder.

Step 5: Delete the original container folder for your app.

Step 6: Restart the app to see if the issue is resolved.

As a last resort – and we mean that quite literally – if you see this error every time you run an app, you could reinstall macOS.