This copy of the Install macOS High Sierra.app application is damaged and can't be used to install macOS

I ran into this today on a MacBook Pro (15-inch, Mid 2010) while attempting to perform an erase hard drive and install from a USB flash drive. I tried both OS X 10.11 El Capitan and macOS 10.12 Sierra. After I set the date (ntpdate -u time.apple.com) I was able to perform an erase and install from USB of 10.11 and then an erase and install of 10.12. I wanted to validate that my USB flash drives were not the problem.

Just set the date on Terminal inside the installer

date 0712122318

For that example, it would set the date as “July 12 2018 at 12:23”
From http://osxdaily.com/2012/07/04/set-system-time-mac-os-x-command-line/

Problem resolved, the error message "This copy of the Install macOS High Sierra.app application is damaged and can't be used to install macOS" does NOT necessarily indicate that anything is wrong with the actual installation media.

No instead this little gem is Apple's way of telling you that either:

1) You are installing on non authentic Apple hardware

2) Your Apple hardware needs a firmware update, which requires you to first install the original OS X version that came with your hardware.

In the case of those 3 2012 Mac Mini's that would not install High Sierra for me, I had to install Mountain Lion first, after that I could erase the drive again and do a clean install of High Sierra with no problems.

Thank you Apple for the quality of your 'error' messages.

This fixed my problem too after I had just replaced my hard drive with an SSD, MacBook Pro 2012:

- create USB bootable high-Sierra on another Mac

- boot my MacBook Pro from usb

- load terminal from utility and set today’s date

- install macOS Sierra

Now installed! Thanks for the tip!

probably.

why do you have the date older than today?

I am replying because I wasted a morning on this. The advice on the forums is not helpful.

If all obvious things fail, e.g. you've checked to make sure the image is not corrupt, etc; the problem is that the machine you are trying to install to has an invalid date. This will cause the installation to fail.

In my case, I changed the main battery at the same time I upgraded to a new SSD to re-install on my old machine. This caused the date to reset to 2001, which causes a conflict with the installer.

To fix this, boot from the USB key and then open a terminal when you get to the install menu. Use the 'date' command to set the system time to the current date and time.

You can then install normally without the error.

thanks! setting the date solved it for me 🙂

Great advice. Used this to successfully install MacOS High Sierra on a Macbook 7,1 via bootable USB (that I created on a Macbook Pro 13,1 using Diskmaker X). I also had to reset the pram to get it to see the USB:

You can reset the pram by doing the following:

1. Shut down the Mac.
2. Locate the following four keys: option, command, p and r. You'll need them in the next step.
3. Power on the Mac, then immediately hold option, command, p and r. You need to do this before the grey screen appears.
4. Hold down the keys until you hear the startup sound twice, then release them.
5. Plug in the bootable USB stick, restart the Mac, and hold option.

After changing the date everything went smoothly.

Thank you so much BLLuten, I've been stuck on this problem for days! Setting the date fixed it!

basicdesigns wrote:

It was one of the recommended solutions in the developer forum for this very problem.

That post recommended restoring the Hosts file to its unaltered condition, and as I wrote, if your Mac's Hosts file has been altered, that could be what's preventing the installation.

Do not disable SIP. Do not alter the Finder. Those subjects are completely unrelated to your concern.

Heck, can I still get a copy of Snow Leopard (I think it was)?

If necessary, yes: Mac OS X 10.6 Snow Leopard - Apple

That Mac's original System Install DVD should accompany it from cradle to grave. If you no longer have it, the retail Snow Leopard DVD may be your only recourse. Fortunately it's only $20.

Downloading and making a bootable USB has worked fine in the past. It even worked this morning. Why would it suddenly become a problem, unless the version of High Sierra downloaded from the App Store is corrupt? Can I get a hash from anywhere?

No.

The answer may depend on the method you used to create it. The only method I rely upon follows Apple's published instructions, not the third party solutions frequently promoted on this site, and it works. In any event that seems to be a moot point; if it's not working for you, it's not a solution worth pursuing.

Why are you answering me? Collins1 posted to disable SIP, I am against all that was proposed by Collins1.

You can not change the hosts file because you have erased the SSD. And you shouldn't whatever they say in the developer forum.