Troubleshooting – What Happened to My macOS?

macbook pro

After I put my MacBook to sleep, like I always do; the following day, I open the lid and it’s off for some reason. I turn it on and it powers up. I select my user account and enter the password. It loads and then freezes/hangs about half way through. It then reboots and loads some weird screen saying and macOS installation failed either restart, shut down, show log/save log.

What the is that exactly? Did my OS got corrupted for some reason? What should I do now?

Best Answer

If you can boot to Recovery HD, then you can check for a local Time Machine back up or external drive backup and make a decision.

  1. Data is most important, so take the Mac to another Mac and use target disk mode or an external drive to get a known good backup off the drive. This assumes your drive or the Mac is failing and this isn’t just a software error and time you spend looking at the logs or trying to fix it delays the chance to save your data on a good drive.
  2. Dig a little into the error and try a reinstall of the os. This assumes the data is intact and you’re Ok risking loss and playing the odds.
  3. Find a technician or spend time learning about the console and boot process and specific boot error (see the logs or boot in verbose mode) to remedy a specific failure in the startup process.
Related Question