It’s rare that applications grind to a complete halt, but if they do, forcing them to quit usually solves the problem and allows you to carry on using your Mac and re-launch the app. To Force Quit any open application, press ç+å+oe. This pulls up the Force Quit window, from where you can select the app you want to force to shut down. If you’d rather Force Quit the app you’re currently using without displaying the window, use ç+å+ß+oe instead. Like we said, on most occasions, this method will fix a misbehaving app.