If an application isn't working and you can't get it to quit, you can force it to quit. When you force an application to quit, you lose any unsaved changes to documents that are open in the application.

There are several ways to force an application to quit:

1. Choose Apple menu > Force Quit, select the application in the list, and click Force Quit.
2. Press the Command, Option, and Esc keys at the same time. Then select the application in the list and click Force Quit.
3. Hold down the Option key and press the application icon in the Dock.

After you force an application to quit, try using it again. If you continue to have problems, you may need to install the application again or contact the application's maker for more help.