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OS X Mountain Lion: If your Mac restarts and the message “Your computer restarted because of a problem” appears

If your Mac restarts and the message “Your computer restarted because of a problem” appears

If your Mac restarts and the message “Your computer restarted because of a problem” appears, an error known as a “kernel panic” occurred. The most likely cause is a software problem. A kernel panic can also be caused by damaged or incompatible hardware, including external devices attached to your Mac.

If your Mac continues to experience kernel panics, follow the troubleshooting steps below.

Note: To print these instructions, open the Help Viewer’s Action pop-up menu (looks like a gear) and choose Print.
  • Restart the computer in safe mode. If the computer successfully starts up in safe mode, choose Apple menu > Software Update, and then download and install any updates available for your computer.

    Start up in safe mode

  • Uninstall any plug-ins or other enhancement software from manufacturers other than Apple. If you recently updated OS X or an app, plug-ins and other software that worked in the past may no longer be compatible. Read the manufacturer’s documentation (including Read Me notes) to be sure the software is compatible with your version of OS X.
  • Reset parameter random-access memory (PRAM).

    Reset your computer’s PRAM

    Apple Support article: Mac OS X: What’s stored in PRAM?

  • Repair your startup disk or your disk permissions, or both.

    Repair a disk

  • Disconnect all USB and FireWire devices, except for the Apple keyboard and mouse. Remove hardware upgrades from other manufacturers, such as random–access memory (RAM) and Peripheral Component Interconnect cards. Then try restarting your computer.

    If this resolves the issue, reconnect one device at a time, restarting your computer after reconnecting each one, until you’ve determined which device is causing the problem.

  • Depending on your type of Mac, use either Apple Diagnostics or Apple Hardware Test. Apple Diagnostics or Apple Hardware Test can tell you if hardware you installed, such as additional memory, is incompatible, improperly installed, or defective.

    If you can’t find Apple Diagnostics or Apple Hardware Test, take your Mac to an Apple Authorized Service Provider.

    Use Apple Diagnostics or Apple Hardware Test

  • If the steps above don’t help, try reinstalling OS X.

    Reinstall OS X

    Note: If you moved or renamed an OS X system file or folder, you must reinstall OS X. It won’t work to just replace the specific item.
Last Modified: Aug 8, 2013
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