One app misbehaves, the rest of the Mac is fine. That is good news: it narrows the problem. Apple’s checklist for an app that freezes or quits unexpectedly covers most cases, and it starts with the simplest steps.
1. Force quit the app
If it is unresponsive, choose Apple menu, then Force Quit, select the app and click Force Quit. You may lose unsaved changes. Our force quit guide shows other methods too.
2. Reopen it
If the app quit on its own, click Reopen in the dialog that appears.
3. Restart your Mac
Apple menu, then Restart.
4. Make sure the app is compatible
The app has to work with your version of macOS. This matters most right after a major update. See what to do when a Mac misbehaves after an update.
5. Open a different file
Apple points out that the original file may be the problem. Try another file in the same app.
6. Check for updates
Update both the app and macOS.
7. Disconnect new devices
Unplug anything you just connected, such as a printer. It may not be compatible with your version of macOS.
8. Remove third-party plug-ins
Apple says to uninstall plug-ins or enhancements from other manufacturers. After updating the app or macOS, a plug-in may no longer be compatible.
9. Diagnose hardware
Run Apple’s diagnostics to check whether hardware such as added memory is incompatible, improperly installed or defective.
If it only happens in one app
Contact the app’s developer with the macOS version and a description of what you were doing.
Frequently asked questions
Will force quitting lose my work?
Apple warns you may lose unsaved changes.
Why does an app crash after an update?
It may not be compatible with your macOS version, or a plug-in may no longer work.
Sources
Last checked November 3, 2026. Apple changes its instructions between updates, so if a menu looks different on your Mac, check the linked Apple page.
