Mac App Crashing or Won't Open? Fix It Step by Step
An app that quits unexpectedly or bounces in the Dock and never opens is annoying, but it rarely means your Mac is broken. Start with a clean quit and an update, and only reinstall once the simple fixes have failed.
Follow these steps
- Force quit the app, then reopen it. Press Command, Option, and Escape together, select the app, and click Force Quit. Then reopen it normally. This clears a stuck process without changing any of your files.
- Restart your Mac. If force quitting does not help, restart the Mac. A restart clears temporary states that can keep an app crashing, and it is worth trying before any deeper fix.
- Update the app and macOS. Open the App Store and check for app updates, and in System Settings check for macOS updates. Crashes are often fixed by an update, especially after a macOS upgrade leaves an old app behind.
- Check the app's permissions. Open System Settings, then Privacy and Security, and confirm the app has the permissions it needs, such as access to files, the camera, or the microphone. A missing permission can make an app quit as soon as it tries to use that feature.
- Try the app with a different file or account. Open a different document, or sign out and back in if the app uses an account. If only one file crashes it, the file may be damaged; if every file crashes, the app itself is the problem.
- Delete and reinstall the app from a trusted source. Delete the app, then reinstall it from the App Store or the developer's official website. Reinstalling replaces damaged app files while your documents, which live separately, stay put.
- Note any Gatekeeper message and what it means. If macOS says the app cannot be opened because the developer cannot be verified, it is blocking software it does not recognise. Only override this for software you deliberately downloaded from a source you trust, and never for a file from a random link.
What NOT to do
- Do not override Gatekeeper for an app from an email attachment, a pop-up, or a download site you do not trust. That warning exists to protect you.
- Do not delete an app's Library files or preferences at random. You can lose settings and data that a simple reinstall would have kept.
- Do not download a fixer or cleaner that claims to repair crashing apps. It is more likely to add new problems than solve the old one.
If the app now opens and stays open, you are done. If it still crashes after a reinstall, check the developer's support page for a known issue with your macOS version, or try an alternative app for the same job.