'Installation Failed' on Mac

This page is a how-to to solve the problem:

Mac OS will not reboot - an install log is shown and the message 'Installation failed'

Steps to Resolve

To re-install OS - restart the Mac while pressing CMD+Shift+R.

You will be presented with a startup OS that will require you to reconnect to the network. Follow the steps to reinstall the Operating System to your computer.

If you reinstall the Operating System, no data should be lost (ie you will NOT wipe your hard drive, whichever one you choose).

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