Me and my unorganized thoughts

How to reinstall macOS when you get “application is damaged” error

Today I was trying to reinstall an older Mac Mini and installation keep failing with error: “This copy of the Install macOS application is damaged, and can’t be used to install macOS.”

I have tried Yosemite, High Sierra beta (the latest one b6) but still the same error happened so I started wondering why it would fail. One look in the terminal on date and time showed that Mini thought it’s 2001 so package couldn’t be verified and thus installed as verification failed.

So I run following command to set today’s date and time:

date 0818134217

After the date and time were updated to today’s date and installation went on without any problems.

Here is how to use date command:

date — display or set date and time

date [-jnu] [[[mm]dd]HH]MM[[cc]yy][.ss]

So in my case it was:

  • 08 – month
  • 18 – day
  • 13 – hour
  • 42 – minutes
  • 17 – year

This might save you some time.


  1. James

    Thanks for this – saved me a lot of mucking about.

    • amar

      Great, I know I lost quite a lot of time to get it working, message is not self explanatory. I have redownloaded installation files multiple times.

  2. Gene

    Yes man it really helped after upgrading ssd , when I disconnected battery cable it seems forgot the date ,

    • amar

      Great, glad it helped.

  3. Bridget

    Brilliant – couldn’t get this new install working, went through a couple of USB’s and kept getting error message. Like Gene above I was installing to a new SSD and your BRILLIANT and easy solution got this all working. I’ve trawled the internet and haven’t found anyone who has shared this info. Thanks!

    • amar

      You are welcome! 🙂

  4. Roman

    The battery in my Macbook Pro 13″ mid 2010 has died recently and the laptop was laying around gathering dust without any power to its SMC, which led to system clock reset to year 2001, and that caused macOS High Sierra installer to fail. This post just saved me a lot of time and USB stick memory wear! Thank you big time, author!

    • amar


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