Mac OS sierra app is damaged

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bootable drive with the plist deleted but now it is impossible because my mac thinks that the installation package is no longer valid, HALP!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 was what I needed. I never considered the computer time would be off, or that it being off would cause the installer to report that the installer is bad, rather than simply updating the machine's time as part of the update.

That did help a little, I deleted the plist file from the prepared usb stick.

On installing i got a new error "the installer payload failed signature check"

So in utillities i opened the terminal and typed ntpdate -u time.apple.com

This sets the internal clock end from there everything went smooth

i got this from the tip in this site

https://www.macworld.com/article/3097533/macs/installing-os-x-what-to-do-when-th is-copy-of-the-install-os-x-application-…

I have the same issue, but also the App Store thinks that Sierra has already been downloaded and won't let me try again. It doesn't show on the "Purchases" list.

"FAILED TO DOWNLOAD"?

35GB's of available disk space is cutting it too close. Free up storage to at least 50GB's.

macOS - How to Upgrade - Apple

Thank you.

O... and... I miss Leopard, I miss Steve Jobs era. Apple has become a rotten marketing monster.

Thank you Thubredhal! I've been searching everywhere for this info.