Occasionally, you might experience problems using your Mac. Here are some examples:
An error message appears on screen when you attempt to perform a task.
An application "unexpectedly quits" while you are using it.
An application simply won't work correctly.
You can't open a certain file.
Your computer "freezes" or "locks up"—either at startup or while working with an application— making it impossible to move the mouse pointer, quit an application, or even properly restart the computer.
These are examples of problems you might experience. Although these problems may be caused by any number of things, there are some techniques you can use to narrow down the cause and fix the problem. That's what troubleshooting is all about.
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