Mac OS sierra app is damaged

I think I have the answer.

Summary

1. Turn off SIP

2. Install High Sierra

3. If you enjoy pain, turn SIP back on.

Detailed steps

1. Restart the computer

2. Immediately hold down CMD+R and release it when the Apple logo appears.

3. Select Utilities | Terminal from the menu bar

4. On the command line type “csrutil disable”

5. On the command line type “reboot”

6. Download and install High Sierra

If you enjoy pain in your nether region, repeat steps one through five, but type “csr enable" in step four. We’ve been running OS X without anything resembling SIP for years and years, so it is probably safe to run without it.

If you have reset NVRAM PRAM before the installation, than date and time was been reseted.

Wrong date is one of reason to cancel installation with "This copy of the Install macOS Sierra.app application is damaged, and can't be used to install macOS"
If you are installing macOS using USB, run Terminaland fix System Date using command: date {month}{day}{hour}{minute}{year} <enter>
Example: date 030223592018
Means March, 02, 23:59, 2018

after that select: Install macOS ... again.

It really works for me.

I was having this issue running off of a Bootable USB drive with a brand new SSD drive installed. I used disk utility to repair everything I could and rebooted but same issue. I then followed these instructions http://www.macworld.com/article/3097533/macs/installing-os-x-what-to-do-when-thi s-copy-of-the-install-os-x-application-c… and while connected to a hardline set the time using the Terminal command ntpdate -u time.apple.com. My install proceeded as expected as soon as I did this.

This was the only thing that worked for me. I had tried every other suggestion in this forum, and all of them came up empty. I even used Onyx once, and things still didn't work. But when I saw you ran Onyx 4 times, I decided to try to do it multiple times as well. After running the Automation scripts 3 times, I finally was able to install Sierra. So thank you for sharing that you ran it multiple times! Worked for me! (Finally!)

slvrstrk got it right: the problem in my case was that the time and date were wrong. I connected to a network, ran ntpdate in Terminal as they described, then ran the installer and all was well. My guess is that the installer is validating itself cryptographically using a certificate, and the certificate appears invalid if the date is off.

Before starting installation run Terminal and check the system date using date command. If it is not okey than change the date following https://bensmann.no/changing-system-date-from-terminal-os-x-recovery/.

This solution worked for me. My laptop was very old and after opening up terminal it appeared that the date was off by a large amount. I set the date as per the link posted by user, blgnksy, restarted the laptop and now my usb install process progresses past the error. Hope this info helps!

I am try restore a completely damaged disk - was trying to install.

Get the same message as above. So I remove the stated file ... Then it cannot even create the boot usb drive.

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Install\ macOS\ Sierra --applicationpath /Applications/Install\ macOS\ Sierra.app

Password:

/Applications/Install macOS Sierra.app does not appear to be a valid OS installer application.

If I just restore the file, it at least creates the drive.

I am trying to install Sierra on around a 4/5 year old MacBook Pro.

Its weird this issue goes on, as High Sierra is out for almost a week.

So... Onyx is a solution, despite somebody using here the „I” argument (I would not use Onyx). Sierra and High Sierra are more... I don't know, tight? in many ways, they brought many things to a new level, so a flawless base for installation is necessary. If this routines for repairing index, permissions and the rest doesn`t suits to the troubled users, I recommend partitioning the hard disk, moving all essentials documents on the non-system partition and proceding to a clean install. It may imply a bit much work, having to reinstall back all applications, but its just a matter of hours - less then spending days riding around the internet and chasing for smart solutions.

What if I have to make a bootable thumbdrive? I am trying to download macOS Sierra to my old macbook from 2009, which has all the right hardware to take the download, but I get the corrupted/damaged error. I tried to make a new bootable drive with the plist deleted but now it is impossible because my mac thinks that the installation package is no longer valid, HALP!

Not working for me. After deleting the file I now get an error saying...

"An error occurred while preparing the installation. Try running this application again."

It has happened on multiple machines as well. Most machines will update without issue, but a few randoms won't.

All are 2.5GHz i5 Mac Mini with 8GB RAM. All or originating from identical 10.9 master image.

THANK YOU! This helped me. The problem was that the machine thought it is in 2001. So using the date command to set up the correct date and time fixed this problem. I was not able to use the ntpdate as the computer wasn't online. I wasted multiple hours trying to fix this and tried a lot of things, but this helped.

Okay, the problem can be solved by setting the date before installing. I have four questions for the developers of the installation program:

1. What did you do in previous versions of the operating system installer that you forgot to do in this one?

2. Is there a bug in the software that updates the time over the internet? How else could the date and time be wrong for everyone?

3. Why wasn't the installation program written to ignore the time?

4. Why wasn't the installation program written to set the time as the first step?

The most positive spin I can put on this is that it is only natural that this problem would exist. Management is thinking too much about us and therefore has a policy of releasing a new version every year. They aren't thinking about the developers enough because a year is too short even for super-developers from Krypton. Management shot itself in the foot because the one-year mandate is supposed to please customers but results in updates that don't please customers!

Apple management needs to change the mandate so that they put out a new version every TWO years.

This totally worked for me! Thank You!

My Scenario: 5 year old MacBook Pro was dropped and damaged the hard drive. I put a new one in and made a bootable USB drive to reinstall High Sierra. It kept giving me the "This copy of the Install macOS High Sierra.app application is damaged, and can't be used to install macOS." I ran "ntpdate -u time.apple.com" in terminal as indicated and it worked fabulously!

Thank you this fixed my issue on high sierra. i deleted the installnfo.plist and it worked 🙂 i was trying to do a clean install and it kept saying image is damaged, but put the image to a usb and i deleted the installnfo.plist file and then it worked thanks @thubredhal