OS X Mavericks: If your Mac restarts and a message appears
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If your Mac restarts unexpectedly, an error known as a “kernel panic” occurred. After the restart, you’ll see a message that your computer restarted because of a problem.
The most likely cause is faulty software. A kernel panic can also be caused by damaged or incompatible hardware, including external devices attached to your Mac.
Note: To print these instructions, open the Help Viewer’s Action pop-up menu (looks like a gear), then choose Print.
- If the kernel panic is caused by a known problem, the faulty software is identified. To make sure that this software doesn’t continue to cause kernel panics, move it to the Trash.
If the faulty software is not identified and your Mac continues to experience kernel panics, follow the troubleshooting steps below.
- Restart the Mac in safe mode. If the Mac successfully starts up in safe mode, choose Apple menu > Software Update, then download and install any updates available for your Mac.
- 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).
- Use Disk Utility to repair your startup disk or your disk permissions, or both.
- 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 Mac.
If this resolves the issue, reconnect one device at a time, restarting your Mac after reconnecting each one, until you determine which device is causing the problem.
- Use Apple Diagnostics or Apple Hardware Test. These apps can tell you if hardware you installed, such as additional memory, is incompatible, improperly installed, or defective.
- If the steps above don’t help, try reinstalling 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 or rename the specific item.
Last Modified: Nov 11, 2015