The three messages that give the problem away
You boot from a USB stick or Recovery, open “Install macOS” and, instead of installing, you get one of these:
- “This copy of the Install macOS High Sierra application is damaged, and can’t be used to install macOS.”
- “No packages were eligible for install.”
- “This copy of the Install OS X El Capitan application can’t be verified. It may have been corrupted or tampered with during downloading.”
A fourth variant shows up a lot with Sierra: “The installer payload failed signature check”. All four mean the same thing, and they mostly hit El Capitan, Sierra, High Sierra and Mojave, although they can appear with any version since Leopard.
The good news: if you didn’t get the prohibitory symbol (the crossed-out circle) at boot, the version is compatible with your Mac. The installer isn’t broken and your Mac isn’t “too old”. It’s something else.
The real cause: an expired certificate (not planned obsolescence)
Forums often claim that “Apple blocks it so you buy a new Mac”. That’s not it. Every macOS installer is digitally signed, and that signature relies on a certificate chain with a start date and an expiry date. Before installing, macOS checks that the signature is valid on the date the Mac’s clock shows.
On October 24, 2019 the intermediate certificate Apple used to sign its installers expired. From that day on, any copy signed with it — even one you’ve kept on a USB stick or drive for years — stops validating with today’s date, and the installer reports it as “damaged”. Apple re-signed the versions it still distributes with a new certificate valid until 2029.
That leads to the situations I see on the bench:
| Situation | What happens | Fix |
|---|---|---|
| Old installer (downloaded before Oct 2019) | Its certificate has expired as of today | Download it again from Apple (re-signed) or set a date before Oct 24, 2019 |
| Mac clock in the past (2000, 2001…) | The certificate is “not yet valid” on that date | Set today’s date with date; check the clock battery |
| Re-signed installer + correct date | Should install with no errors | If it fails, corrupt download or incompatible Mac: download again |
On 2006–2012 iMacs and MacBooks the PRAM battery is very often dead. With no power, the clock resets to 2000 or 2001 and the installer fails with exactly the same messages, even with a fresh copy. That’s why the first step is always to type date in Terminal and see what date the Mac thinks it is.
Fix 1 (recommended): download Apple’s re-signed installer
Apple keeps an official page to download previous versions. From there:
- High Sierra (10.13) through Sequoia (15): direct App Store link.
- Sierra (10.12), El Capitan (10.11), Yosemite (10.10), Mountain Lion (10.8) and Lion (10.7): a
.dmgdownloaded in the browser; inside is a.pkgthat puts “Install OS X…” in Applications. - On a Mac running Catalina or later, also from Terminal:
softwareupdate --list-full-installersthensoftwareupdate --fetch-full-installer --full-installer-version 10.15.7.
With that fresh copy, recreate the USB stick with createinstallmedia. This matters: a USB stick made from an old installer carries the same expired certificate, so retrying isn’t enough; you have to rebuild it. The exact commands per version are in the knowledge base guide.
Fix 2: change the date from the installer’s Terminal
When you can’t download again (Mac without internet, that USB stick is all you have, or the version is no longer offered — Mavericks, for example, isn’t on Apple’s page), you can fool the clock during the install:
- Disconnect Wi-Fi and the network cable, so the Mac doesn’t correct the time online.
- Boot from the USB stick or Recovery and, without leaving the installer, open Utilities → Terminal.
- Type
dateto see the Mac’s current date. - Type the new date as
MMDDhhmmYY(month, day, hour, minutes, year). For High Sierra, for example:date 0101010118= January 1, 2018, 01:01. - Quit Terminal from the Terminal menu → Quit Terminal (closing the window isn’t enough) and run the installer again.
The date must fall within the validity period of your copy’s certificate: after it was signed and before it expired. For copies older than October 2019, what works is the version’s release date or January 1 of the following year. This table has both options:
| Version | Name | Released | Release date | Alternative (community) |
|---|---|---|---|---|
| 26 | macOS Tahoe | Sep 15, 2025 | date 0915000025 | — |
| 15 | macOS Sequoia | Sep 16, 2024 | date 0916000024 | — |
| 14 | macOS Sonoma | Sep 26, 2023 | date 0926000023 | — |
| 13 | macOS Ventura | Oct 24, 2022 | date 1024000022 | — |
| 12 | macOS Monterey | Oct 25, 2021 | date 1025000021 | — |
| 11 | macOS Big Sur | Nov 12, 2020 | date 1112000020 | date 0101010121 |
| 10.15 | macOS Catalina | Oct 7, 2019 | date 1007000019 | date 0101010120 |
| 10.14 | macOS Mojave | Sep 24, 2018 | date 0924000018 | date 0101010119 |
| 10.13 | macOS High Sierra | Sep 25, 2017 | date 0925000017 | date 0101010118 |
| 10.12 | macOS Sierra | Sep 20, 2016 | date 0920000016 | date 0101010117 |
| 10.11 | OS X El Capitan | Sep 30, 2015 | date 0930000015 | date 0101010116 |
| 10.10 | OS X Yosemite | Oct 16, 2014 | date 1016000014 | date 0101010115 |
| 10.9 | OS X Mavericks | Oct 22, 2013 | date 1022000013 | date 0101010114 |
| 10.8 | OS X Mountain Lion | Jul 25, 2012 | date 0725000012 | date 0101010113 |
| 10.7 | Mac OS X Lion | Jul 20, 2011 | date 0720000011 | date 0101010111 |
| 10.6 | Mac OS X Snow Leopard | Aug 28, 2009 | date 0828000009 | date 0101010110 |
| 10.5 | Mac OS X Leopard | Oct 26, 2007 | date 1026000007 | date 0101010108 |
If the first date doesn’t work, try the “Alternative” column or move the year up by one (e.g. date 0101010117 → date 0101010118). One important caveat: if your copy is Apple’s re-signed one, don’t give it an old date, because its new certificate only became valid in late 2019 and a 2017 date makes it “invalid”. With that copy, the right date is today.
On Intel Macs, reset NVRAM: at power-on hold Option + Command + P + R for about 20 seconds. If the clock goes back to 2001 after shutting down, the PRAM battery is dead; you can still install by setting the date on every boot, but it’s worth replacing.
After installing: set the clock back to the real date
This isn’t optional. A macOS running with a fake date stamps files wrongly, confuses Time Machine and breaks secure browsing (website certificates won’t validate either). When you’re done, connect to the internet and enable System Preferences → Date & Time → Set date and time automatically. It’s safest to use the date trick only on a clean install, not on a system holding data you care about.
And if what you wanted was a newer version than your Mac officially supports, another route is to install the latest version it does accept and update from there through Software Update.
Frequently asked questions
Why does the macOS installer say it is damaged if I just downloaded it?
It is almost always an expired certificate, not a corrupt file. On October 24, 2019 the intermediate certificate Apple used to sign its installers expired, and any copy downloaded before that date stops validating with today’s date. It also happens when the Mac’s clock is in the past, for example in 2001 because of a dead PRAM battery.
Does Apple block old versions to force you to buy a new Mac?
No. It is a signing-certificate validity problem. Apple published re-signed installers with a certificate valid until 2029 on its official download page; if your Mac supports that version, it installs with today’s date and no tricks.
What date should I set with the date command to install High Sierra?
If your installer is a copy from before October 2019, a date between its release and October 24, 2019, for example date 0101010118 (January 1, 2018). If you downloaded Apple’s re-signed installer, do not change the date: leave it at today.
Is changing the Mac’s date dangerous?
Only if you leave it that way. Do it from the installer’s Terminal, offline, ideally on a clean install, and turn automatic date and time back on afterwards. A fake date on a system in use skews file timestamps and confuses Time Machine.
Want me to do it?
If you have an iMac or MacBook stuck on an old version, in Cartagena or through remote support, message me on WhatsApp. The step-by-step commands, with copy buttons, are in the knowledge base.
Sources
- Apple — Download and install current or previous versions of macOS
- Apple — How to create a bootable installer for macOS
- The Eclectic Light Company — Why old installers may not work
- 9to5Mac — macOS installer “damaged” error after the October 2019 certificate expiry
- Gist de pjobson — tabla de fechas por versión
- Reddit r/MacOS — “The installer payload failed signature check”
- Foro Divergente27 — fechas probadas en MacBook blanco e iMac 2009