Mac Installation Errors You May Encounter and How to Fix Them

With every new release of the Mac operating system, there always seems to be a few installation errors that are encountered by enough people to make us wonder how the OS managed to get through the beta process. The answer can usually be attributed to the difference in the relatively small number of beta users versus the large number of users downloading and installing a new official release of the macOS. When all those new users start to install the OS, the sheer number of Mac hardware, peripherals, and software makes it very likely that some bug that managed to sneak through the beta process will rear its ugly head in the release version.

In this guide, we’re going to look at some of the installation problems that tend to occur with new releases of the Mac operating system. With any luck, you may be able to either correct the issue, allowing you to finish the installation, or prevent the issue from occurring in the first place.

Installation Issues Commonly Seen with macOS

Before we get too far along, I want to point out the obvious: don’t install a new version of the Mac operating system without having a current backup. Some of the installation issues we’re going to mention can cause loss of data. Having a Time Machine backup or a clone of your current system can be a lifesaver. If you don’t have a backup system in place, I highly recommend investing in one before you install a new version of macOS.

You can find a large number of external enclosures, drives, and SSDs, as well as a portable and easily-carried-with-you Envoy Pro EX high-performance USB 3 or Thunderbolt bus-powered SSD storage.

With the backup recommendation out of the way, let’s get started with the error messages.

Could Not Write Installation Information to Disk

This message usually shows up as a sheet that drops down from the macOS or OS X installer shortly after you start the install process. It may seem odd but the usual cause is a corrupt installer, and simply deleting the installer app and downloading a new copy will likely fix the issue. The error message seems to occur most often when the Mac installer is downloaded from a third-party site. This is a good reason to download the official copy from the Mac App Store, or join the free public beta program if you want to try out a new version of the Mac OS early.

Other possible causes include a damaged boot drive. Try using Disk Utility’s First Aid capabilities to test and repair your disk, as outlined in First Aid: Verify and Repair HFS+, APFS Drives with Disk Utility.

Could Not Find Installation Information for This Machine

You may run across this error message when you’re performing a clean install of the Mac OS and have erased the startup drive. Normally, when you perform a clean install and erase the startup drive, you do so while running the macOS installer from another boot drive, perhaps a USB flash drive that you have cloned the installer to.

If the installer has a problem, you may find yourself forced to reboot and use the Recovery Partition or the Internet Recovery System built into your Mac. It’s at this point that the Could Not Find error message is displayed.

The usual cause is a simple one; your Mac isn’t connected to your local network and the Recovery process is trying to access Apple’s servers to download the software needed for installation. Instead of telling you your Wi-Fi or Ethernet network isn’t working, the installer displays the above message.

The fix is to make sure you’re connected to your Ethernet network, or have your Wi-Fi password on hand. Restart your Mac while holding down the Command + R keys to enter recovery.

If you don’t automatically connect to your network, you’ll be asked to either supply the Wi-Fi password or select another method of connecting to your network.

If you connect by Wi-Fi, make sure it’s selected, and then supply the password.

You should now be able to continue the recovery process and reinstall the operating system.

Computer is Incompatible with the Operating System You Are Attempting to Install

This error message is an oldie, but could be seen by someone upgrading from OS X Yosemite and earlier to OS X El Capitan or later. Start by checking to see if your Mac is actually compatible with a newer version of the OS. In some cases, you won’t be able to upgrade because Apple has dropped support for your older Mac. You can check the compatibility lists at the links below.

If your Mac is listed as compatible, you’re running OS X Yosemite or earlier, and you’re still seeing the error message when you attempt to upgrade, chances are your startup drive’s permissions need to be repaired.

You can find instructions on repairing disk permissions in the article: Keep your Mac running its best using these simple tips.

macOS Could Not Be Installed on Your Computer

This is a similar problem to the incompatible error listed above, except it involves all Macs running macOS Sierra and later. Just as before, start by making sure your Mac is compatible with the macOS version you’re installing. You can use the same links listed above to check compatibility.

Once you’re sure your Mac is on the compatibility list, it’s time to check your time, or more specifically, your Mac’s time and date settings. A rather obscure issue with the Date & Time preferences can prevent installation of a new version of the macOS.

Launch System Preferences by selecting the System Preferences icon in the Dock, or by selecting System Preferences from the Apple menu.

Open the Date & Time preference pane.

Make sure the date and time are set correctly. Be sure to verify that the time zone is also correct.

To make changes, you’ll need to unlock the padlock with your administrator password.

Make any changes needed to ensure the settings are correct. If you have a reliable Internet connection, it’s best to use the option to “Set date and time automatically.” Use the dropdown menu to select a local Apple timeserver.

If you’re not able to access the System Preferences to fix the time and date issue, you can do so from the Recovery system by using the Terminal app, which is available from the Recovery menu. You can find instructions for using the Recovery system in the article: Rocket Yard Guide: Everything You Need to Know About OS X Recovery. The instructions for using Terminal to make time changes are available in: Tech Tip: ‘An Error Occurred While Preparing the Installation’ Fix.

When All Else Fails…

There are a number of generally helpful troubleshooting tips that can get a wayward installation back on track. While not tied to a specific installation process, these tricks have been known to correct an underlying issue and get a Mac user going again:

First Aid: Run a First Aid repair of your startup drive (assuming the startup drive is the target of your installation). Follow the instructions in: First Aid: Verify and Repair HFS+, APFS Drives with Disk Utility.

Safe Mode: You should also consider starting up in Safe Mode. Safe Mode will perform some basic system checks, including testing your Mac’s hardware, startup disk, and system software. It will also disable most third-party extensions that may be interfering with the installation process: Safe Mode & Single-User Mode: What They Are, How to Use Them.

Startup Disk settings: Once in a while, the Mac’s startup disk can be set incorrectly because of an installation error. When this happens, the installation won’t be able to complete because it will attempt to boot from the wrong drive. If you’re having install problems you can’t figure out, use System Preferences, Startup Disk to check that it’s set correctly.

Reset NVRAM and SMC: The NVRAM (early Macs used PRAM), combined with the SMC, holds a great deal of the Mac’s system settings. Sometimes these settings can get out of whack, and have unusual effects on a system installation, not to mention causing your Mac to be a bit goofy in general. Resetting them to their default states can sometimes correct issues you may be having. You can find out more in the article: How to Reset NVRAM, PRAM, SMC on Your Mac.

At this point, you should have been able to fix the installation issue you may have encountered. If not, it may be time to restore your Mac’s data from your backup, and take a fresh start at installing your new or updated OS.


  • Hey! I’m in a really sticky situation right now because in my job they made me fix this old 2008 Imac and when I checked it, it seem pretty easy but now I’m stomping thru lots of mistakes.

    Long story short, I created a bootable usb with snow leopard and el capitan (both in different usbs) and when I start it up with the option key pressed, then click on the bootable usb with the OS: the Imac gives me an kernel warning and I’ve been scared to try anything else.

    (The thing is that I have no access to wifi, the ethernel hub on the imac doesnt work and I am working with a windows keyboard which gets pretty confusing to me)

    What should I do when this happens? How can I avoid the kernel warning?

  • I tried to delete and reinstall mojave because there appeared a ZEUS trojan. But in the process I touched some key and my computer died or something/ Now all I get is a file picture{folder} flashing in centre of black screen with a {QUESTION MARK SYMBOL} in the centre of small file pic. Now nothin I do works. HELP! My other iMac works with email

    • Try booting in Recovery mode: Start up holding down the Command and R keys. Then run Disk Utility on the affected volume. Likewise you can start up holding down the Command and P plus the R keys to reset the PRAM. Alternatively, you can restore your system from a Time Machine backup, something you can also do in Recovery Mode. If you didn’t back up your system before upgrading you may be SOL.

  • This blog has definitely helped me to understand the errors and the default faults for the Mac OS el sierra, I have had the error while the installation, It is not booting up but showing an unknown error called Mac Error Code 43, This solution will definitely help me fix the issue and solve the error that I was having.

  • I have the 469 GB OWC SSD on my mid-2013 MacBook Air. When I woke up the Air in the morning, it would not accept my login password. I started in the recovery mode, used disk utility first aid to repair the disk. I tried to reinstall Mac OS but it quits with this message: “macOS could not be installed on your computer. An error occurred while removing the previous system. Restart and try again”. Unfortunately, trying gains gives the same result. The Air will not safe start either. I always get flashing folder with question mark when I shut down and reboot. I also noticed that HD is not detected as startup disk. I started from a bootable external disk and tried Migration Assistant to recover my data and documents. Migration Assistant starts but quits without completing the migration. Is this SSD shot, anyway to recover its contents? I do not have a recent backup.

    • I have the same issue, too. Help please

      • ”I have the 750GB SSD on my mid-2013 ”MACBOOK PRO”. When I woke up the Pro in the morning, it would not accept my login password. I started in the recovery mode, used disk utility first aid to repair the disk. I tried to reinstall Mac OS but it quits with this message: “macOS could not be installed on your computer. An error occurred while removing the previous system. Restart and try again”. Unfortunately, trying gains gives the same result. The Air will not safe start either. I always get flashing folder with question mark when I shut down and reboot. I also noticed that HD is not detected as startup disk. I started from a bootable external disk and tried Migration Assistant to recover my data and documents. Migration Assistant starts but quits without completing the migration. Is this SSD shot, anyway to recover its contents? I do not have a recent backup.” Everthing he told is the same as my machine’s done.

  • Thanks Jeff.
    Will downgrading to High Sierra also be an option to get the RAM back?

  • I have recently erased the data from my Macintosh Hdd. I then tried to reinstall mac os Sierra. When it checks for eligiblity, it says request timed out. I’m not being able to pass through this step. Please help.

  • I have a Late 2012 Mac Mini with 16GB OWC RAM running Sierra without problems since I upgraded the RAM. Right after I installed Mojave, however, the lower RAM slot stopped working: two chimes at intervals. Both 8GB RAM modules work fine in the upper slot (no RAM in lower slot). Any suggestions?

  • I am reinstalling the Mac OS X high sierra in safe mode. I only have 2 minutes left to complete installation. I received an error message saying my internet connection failed. I have internet connection. There’s nothing wrong with it. I do not want to start the 3 hour process of reinstalling this program for the second time. How can I continue installation without having to start all over?

    • Go to and download the High Sierra installer. With that you won’t need an internet connection to reinstall it. That’s assuming you’re doing a clean install. It won’t install over an existing High Sierra system. You will want to back up your existing system first, of course, so you won’t lose any data. Once the clean install is finished you can restore your data using Migration Assistant. This will give you some control over the files you want to restore. For a more granular restore you can use Carbon Copy Cloner. I’m assuming since you are reinstalling the system you won’t want to restore the existing system files because that would include whatever corruption you are trying to work around. I’m only guessing here since you didn’t say why you are reinstalling.

      Another way to reinstall over the Internet is by restarting in Recovery Mode (is that what you meant by safe mode?) That will require you to wipe your hard drive. If you’ve done that I hope you have your data backed up. You must have a working system since you were able to post here—unless you used an iDevice.

    • Hi Candace,

      Were you able to solve this problem ? I’m having the sam error.

  • I have an error msg “an error occurred installing MacOS” after I erase my MacBook for factory rest. What should I do?

  • Sometimes you need to set the date to some previous date which is before the Apple Update’s internally coded “expiration date.” This happens if you have an old OSX version that you are trying to install. There are lists of those somewhere on the net…

  • Need guidance please. I’ve got a macbook pro mid 2010. I was preparing a new SSD (Samsung EVO) by following the appropriate instructions for formatting and partition followed by installation of OS El capitan as is running currently. I then used apple’s software to copy the disk from the old HD to the new SSD and once completed on booting it it is running OSX 10.6.8 and I’ve lost data for approx 2 years.
    I’ve tried rebooting from the original drive and that has also done a ‘time jump’ back 2 years or so. I did a time machine backup before starting any of this.
    Was it that my time machine backup was not right?
    Can I rectify and restore what I’ve lost?

    Many thanks in advance

    • Even if you did a clean install of El Capitan it would not explain why you are seeing OS X 10.6.8. OS X 10.6.3/4 was the original system on your computer. Still, it’s hard to know where the 10.6.8 came from, unless Time Machine has been disabled or disconnected for the last 8 years or so. What is the date of your latest Time Machine backup? If it’s recent you can erase the SSD and restore from Time Machine. You could restore your hard drive as well. You say you installed El Capitan, as is running currently, but from where did you install El Capitan?

      This is an example of where one backup is not enough. I use Time Machine but I also use Carbon Copy Cloner to keep a recent clone. It’s faster and easier to restore from a clone than from Time Machine—though a Time Machine backup should be more recent, as a backup is made every hour, even if the backup drive is not connected.

      This also shows a problem with using a laptop computer. Since it a portable computer, it may not be hooked up to a backup drive as often as it should be for decent security. A Time Machine backup drive is of little use if you don’t hook it up to your laptop regularly.

  • Am trying to upgrade Lion to Sierra. The download page says Sierra is “Installed”. I launch the installer, say I agree, then click on “Install”. It asks for a password. Whatever I type for the password, including the correct one, it just loops back to the “Install” button. Nothing else happens.

  • Command-R reinstall of OSX El Capitan on mid-2009 MacBook Pro after a hardrive erase. Repeated installation requests results in this message: “This item is temporarily available. Try again later.” Hopefull this is not forever as this is the highest OS compatible for this MacBook. Any suggestions on when this OSX will be available?

    • Did you dispose of your El Capitan installer after upgrading to macOS 10.11? It was in your Applications folder. Better yet would be to reinstall using Time Machine or a clone of that OS. If you don’t have a backup, they you may have a friend who has a copy of the installer. Failing that, you’ll just have to wait and hope the absence of El Cap isn’t permanent.

  • On a options-command-R install of a new OWC 1Tb SSD drive in my 2015 iMac, the screen says can’t find disk (the new SSD disk) when I try to restore from a TimeMachine thunderbolt Drive. Any fixes for this?

  • I haven’t found this helpful as the error coming up on my screen is not included. This is what I’m getting

    “You may not install to this volume because it has damaged core storage user”

    Please advise how to deal with this error

    • The error message you received can occur if you were using FileVault at some point in the past. Try opening System Preferences, Security & Privacy and selecting the FileVault tab. If you see a note that says “Some users not authorized”, you can open the padlock icon, enter your administrator password and authorize any listed user.

      You can also try disabling FileVault before you install if the above does not work.


  • I hate your updates. Why can’t we continue with what we have. My photos are missing and whenever I plug my phone into the computer it beeps and is not recognized. I don’t have the time or patients for an apple phone. I’m becoming thoroughly frustrated with it. Maybe my next won’t be an iPhone.

  • Installed Mojave on my late 2012 Mac Mini with 16GB OWC RAM installed. Halfway through the install the mini started with the 3 beep cycle. After some experimentations, the Mojave installation resumed with 1 original RAM module in top tray. Any remedies to get the 16GBOWC RAM to work again?

  • My Mojave upgrades have been fraught with the welcome/startup app hanging. Looking at /var/log/install.log the only error was an “error 22” on remounting the volume. I replaced the drive and that solved it, but the first patch beta saw error 22 come back and I had to wipe the drive and reinstall.

  • How about this (going from 10.13.4 to 10.13.6):

    “An error occurred while loading the installer resources”

    Oddly (or, not so, because Apple..) enough no error message was written to the install.log.

    system.log says (heavily trimmed)…

    systemstats[51]: assertion failed: 17E199: systemstats + 914800: 0x40[1]: Caller not allowed to perform action: plugin-containe.525

    …but what does this mean? I do know 17E199 is the kernel for macOS 10.13.4. Maybe a sandboxing problem? And probably the assertion failure has no connection to the launchd error.

  • The Mojave beta installer will reformat your hard drive, if you’re using one, to APSF. That doesn’t mean that the final release will do so, but there’s no way to prevent it at the moment. The script you could use with High Sierra doesn’t work with Mojave. Of course, if you’re installing on an SSD this isn’t a problem. But APSF doesn’t work well on a mechanical hard drive. Not right now, anyway. This isn’t an issue on a Fusion Drive (I hope), as APSF won’t install, though, supposedly, Mojave will.

    So there’s even more to look out for with the Mojave upgrade. I’ll be reading the fine print. And watching what happens to early adoptors. ;-)

    My workaround was to clone the Mojave beta to an HFS+ partition and run it from there. So, this is just one more issue to watch out for. Unless I hear of a change I’ll be installing the release version of Mojave on a test platform, just as I’ve doen with the beta.

    • “The Mojave beta installer will reformat your hard drive, if you’re using one, to APSF.”

      APSF is a stupid design. You could create 100 copies of an important file, and you really stil have only 1 copy of the file with 100 pointers to it.

  • You leave out the pain that will be encountered if you have a tower MacPro 5,1.

    You will need to purchase a new video card that is Metal-compatible, appropriate card power connectors from eBay, and shut off FileVault.

    Then you have to do the following:

    1) Remove old video card and install new card
    2) Run Mojave installer
    3) When told you need a firmware update, read the instructions, but when your Mac shuts down, uninstall the new card and reinstall the old card
    4) Follow the firmware update instructions
    5) When your Mac reboots following the firmware install, shut it down
    6) Reinstall the new video card
    7) Restart the Mojave install

    Note the firmware update for your MacPro will NOT install with the new video card installed, it needs to be the OEM card, but the install will not proceed after that without the new card in place.