As of 2024, both macOS Sierra & High Sierra Recovery + Internet Recovery are still online but are currently broken in two different ways.
In late December of 2023, I started an investigation as to why macOS High Sierra Internet recovery was broken. After figuring out the root issue, OpenCore Legacy Patcher Co-Devloper dhinakg helped me with a wonderful workaround. https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken
That’s not all, now macOS Sierra 10.12.6 Recovery & Internet Recovery are also broken! Keep in mind, the is NOT the date and time issue. This is different issue that can be reproduced every single time. If attempt to install Sierra in recovery, the full installer will download (4.7GB) and then fail with this error:
An error occurred while preparing the installation. Try running this application again.
What the heck could this be? What’s going on?
Table of contents
- What is the root problem?
- How to fix the issue?
- Fix #1 Boot to a NEWER version macOS Internet Recovery!
- Fix #2 Create a macOS Sierra 10.12.6 bootable installer USB (NOTE: this has additional problems as the
createinstallmediainstaller is BROKEN!) - Fix #3 Download the ONLY working version of macOS Sierra from Apple to recovery and use it to install Sierra!
#1 What is the root problem?
What is this error and why is it happening? The error pops up right after you hit the install button for macOS Sierra. The startosinstall app will begin to download the full installer from the Mac App Store.
At the very end, the installer will attempt to mount InstallESG.dmg and fails. The message presented to the user is “An error occurred while preparing the installation. Try running this application again.” The error in the installer log is listed below
osishelperd[571]: Couldn't mount base system dmg! (error code 110) osishelperd[571]: IATOOL: Failed to mount outer dmg osinstallersetupd[565]: Unable to setup bless on disk.
The InstallESG.dmg is in fact corrupt and unable to open. I even extracted the dmg directly from the Mac and tried everything to open it.
You are now completely stuck.
The worst part about this error is that you are left with out any way to recover. You just erased your disk and you don’t have USB installer.
How to fix the issue?
Now that we know what the issue is, how do we fix it?
The 1st: Easiest way is to boot to a newer version of macOS recovery IF your Mac supports it. macOS Mojave and newer Internet recovery version do NOT have this issue. You can follow this article to boot to the LATEST version (Option+Command+R) of macOS Internet recovery https://support.apple.com/en-us/HT204904 NOTE: If you try High Sierra Internet Recovery you will need to follow my fix article: https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken/
The 2nd easiest way is just to boot from a macOS Sierra USB installer. You can make one from this Apple Support document https://support.apple.com/en-us/101578 this is fix #2 below. NOTE: The creates ANOTHER Problem as the InstallOS.dmg has an error in the Info.plist that prevents creation of the Sierra USB installer. To make matters even worse, you can’t unpack the Install macOS Sierra.app on any Mac newer than 10.12! This is a whole other issue that I will address later. But what if you don’t have access to or the ability to create a Sierra USB installer? Follow Fix #3
The 3rd: Download the ONLY working version of macOS Sierra from Apple to recovery and use it to install Sierra! Inside macOS Sierra Internet recovery, we will download InsallOS.dmg unpack it, install it, and then run insallassistant_springboard!
Fix #1 Boot to a newer version of macOS Internet Recovery: 10.13 High Sierra or Newer
The easiest way to fix this issue is to boot your Mac to a newer version of macOS Internet Recovery. Follow the instructions below to boot to the latest compatible version of Intel Internet Recovery. https://support.apple.com/en-us/HT204904
IMPORTANT NOTE: This is ONLY if you WANT to install a newer version. ALSO if your Mac does NOT support High Sierra or newer, follow Fix #2 or Fix #3. You can find out the earliest and latest version of macOS your Mac supports by going to https://everymac.com
NOTE: High Sierra Recovery: macOS 10.13 High Sierra recovery is ALSO broken, follow my fix article for a fix and workaround. https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken/
Fix #2 Create a macOS Sierra bootable installer USB
The 2nd easiest way to fix this issue is to boot your Mac off of a Sierra USB installer. You can download the macOS Sierra installer from this Apple URL https://apps.apple.com/app/macos-high-sierra/id1246284741
Then follow Apple’s instructions to create a USB installer https://support.apple.com/en-us/101578
NOTE: Creation of a macOS Sierra USB installer has 2 major problems. #1 You can now open the installer on High Sierra or newer! #2nd The info.plist has an error in it preventing install. I will cover this later.
Fix #3 Download the ONLY working version of macOS Sierra from Apple directly to recovery and use it to install Sierra!
This fix defiantly takes a few extra steps but does 100% get you out of your jam and starts the macOS Sierra installer. If you are stuck on the screen below, just click the OK button and you will be brought back to the main macOS Sierra menu. From there follow these instructions.
Click on the Menu Bar and select the Terminal.app
I have created a easy way to follow these instructions in macOS recovery if you don’t have a 2nd Mac to use.
Run this command in terminal
curl -L https://archive.org/download/sierraurl/sierra.txt
Now you have a full list of instructions and commands on your screen!
Let’s get started!
Change directory to Macintosh HDcd /Volumes/Macintosh\ HD
Download the macOS Sierra 10.12.6 InstallOS.dmg from Apple.com using curl. Note this is a 4.7GB file and might take a while or fail. If it fails run it again.
curl http://updates-http.cdn-apple.com/2019/cert/061-39476-20191023-48f365f4-0015-4c41-9f44-39d3d2aca067/InstallOS.dmg -o InstallOS.dmg
We need to mount the InstallOS.dmghdiutil attach InstallOS.dmg
Now we need to install the “Install macOS Sierra.app” from the InstallOS.dmg to Macintosh HD volumeinstaller -pkg /Volumes/Install\ macOS/InstallOS.pkg -target /Volumes/Macintosh\ HD
The Install macOS Sierra.app is now in the /Volumes/Macintosh\ HD/Applications folder. We can now start the Sierra installer!/Volumes/Macintosh\ HD/Applications/Install\ macOS\ Sierra.app/Contents/MacOS/Installassistant_springboard
In a few seconds the Sierra installer will start BEHIND the terminal window.
If you don’t see it make the terminal window but DON’T close it as it will stop the installer.
DONE!! Now step through the installer you are good to go now!
Optional: How to Create a macOS Sierra USB installer in macOS Internet Recovery.
Plug in your USB Drive and make sure to backup all data as we are going to ERASE the dive in disk utility
When erasing the USB drive, make sure you click “view” and click “Show all devices”
Make sure to use Format the USB Drive with macOS Extended Journaled and GUID Partition map. Leave Untitled as the default drive name
Go back to terminal
Even though Apple reissued the Sierra installer to fix the Certificate issue in 2019, it has another problem.
The Info.plist CFBundleShortVersionString has an incorrect entry of 12.6.06 when it needs to be 12.6.03
To fix it we can run this command to edit the new entry in.
plutil -replace CFBundleShortVersionString -string "12.6.03" /Volumes/Macintosh\ HD/Applications/Install\ macOS\ Sierra.app/Contents/Info.plist
Now we can create the macOS Sierra USB Installer!/Volumes/Macintosh\ HD/Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Volumes/Macintosh\ HD/Applications/Install\ macOS\ Sierra.app
