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How to Fix macOS Catalina Installation Issues

Installing a new version of the Mac OS is generally a fairly pain-free process; this trend continues with macOS Catalina. Even so, it’s a good idea to review our Rocket Yard guides for a clean install of macOS Catalina as well as an upgrade install of Catalina. You should also take basic steps to ensure you can recover from any install issues you may come across.

The most important of these is to back up your Mac before you start the installation process so that you can recover from any installation issues that may arise. 

If you’ve run into an issue and you didn’t first perform a backup, then with any luck, one of our tips will get you back on track. If it does get your Mac going again, remember to back up your Mac before you go any further.

If you need a storage solution to handle your backups, Other World Computing has a large selection of storage options you can choose from.

With backups out of the way, let’s take a look at some of the common and not-so-common macOS Catalina installation issues you may run into:

macOS Catalina Won’t Install

This is the most basic of Catalina installation errors; it simply won’t install. It may be that the installation won’t start, it seems to freeze during the installation, or it never seems to complete.

The two primary causes are; attempting to install on a Mac that Catalina doesn’t support, or trying to install Catalina on a Mac with limited storage space. 

Supported Macs: Most Macs from 2012 or later support macOS Catalina. The lone exception is the 2010-2012 Mac Pro, whose graphics cards don’t meet Catalina requirements. You can find a full list of supported Macs in the Rocket Yard guide:

Storage Space: You’ll need about 6.5 GB of space just to download the macOS Catalina installer. After that, the amount of space needed is dependent on the type of installation you’re performing: a clean install or an upgrade install.

Get Info pane showing amount of disk space used and available.
You can see how much free space is available on the target drive by highlighting the drive and pressing Command-I

A clean install uses up around 20 GB of storage space. In addition, you need to allow for space for your user data, applications, and future updates. As if that weren’t enough, you should keep at least 10 to15 percent of the startup drive free to ensure adequate performance. I normally suggest a good deal more free space than that, but here we’re just talking about a minimum to ensure you can install and use macOS Catalina.

If you’re performing an upgrade install, you need to make sure the startup drive has enough free space for the installer download (6.5 GB), as well as room for the files the installer will copy to the startup drive during installation. It’s difficult to estimate the size of the free space you’ll need since it’s dependent on the version of the Mac OS you’re running before the upgrade. But if you have 25 GB of free space available, you should be able to successfully perform an install of Catalina.

If you’re tight on free space, consider removing unneeded files using one of these methods:

For some of us, even after we clean out unneeded files we’re still short on free space and need to consider upgrading our Mac’s internal drive or adding an external storage system. OWC has you covered if you need to go this route:

Unable to Write Information to Disk

This message (or a variant) will sometimes show up just after you start the installation process, and is most often caused by a corrupt installer file. The simple solution is to delete the macOS Catalina installer and download a new copy.

Disk Utility's First Aid feature used to check the health of a Mac's drive.
Disk Utility’s First Aid should be run to ensure the startup drive and the target drive do not have any issues that could impact installing macOS Catalina.

A new installer will usually take care of the issue, but there’s another problem that could lead to the same message: a damaged target drive for the installation. If you haven’t already done so, you may want to run Disk Utility’s First Aid tool to check and repair the target drive. You should also run First Aid on the startup drive if it isn’t the target for the installation. You can find instructions on using First Aid in:

Could Not Create a Preboot Volume for APFS

The “could not create preboot volume” along with other APFS (Apple File System) errors associated with converting an HFS+ drive to APFS are rarely encountered, an indication of the maturing of the APFS file system.

macOS Catalina requires the use of APFS instead of HFS+. If you’re upgrading from an earlier version of the Mac OS and you were using HFS+, the installer will convert your target drive from HFS+ to APFS. This, in itself, is not an issue. However, in rare occurrences, you may see an error message.

If you encounter this issue, the cure is easy enough: you just need to erase the target drive using Disk Utility. If the target drive was your startup drive, you’ll need to boot into Recovery mode to access Disk Utility. You may also need to restore your Mac’s data using a recent backup before restarting the installation process.

macOS Could Not Be Installed on Your Computer

This may seem like the same issue we started this article with: having a Mac that is supported by Catalina. The difference is that you already verified that your Mac is compatible (see the link to supported Macs above), but you still see the error message.

Date & Time preference pane.
If the Catalina installer is refusing to run, use the Date & Time preference pane to check that the date and time are set correctly.

If that’s the case, open up the Date & Time preference pane and check its settings. Make sure you have both the correct time and the current date properly configured. The best way to ensure that this isn’t a Date & Time issue is to use the option to “Set date and time automatically.” You’ll find this option in the Date & Time tab of the Date & Time preference pane.

Installation Freezes or Failure to Complete

These are actually two issues; the first is the installer freezing during the first phase of the installation process, and the second is when the failure to complete happens after your Mac has rebooted and attempts to load Catalina for the very first time.

In both cases, the first thing to try is to restart your Mac. This fixes the issue for most users experiencing this problem.

Unfortunately, it’s possible that if the installer hangs up at the worst possible spot, your Mac may not be able to restart because of startup drive issues. If this happens to you, you’ll need to use the Mac’s Recovery utility to repair the startup drive using Disk Utility, and/or reinstall the Mac OS or use your backups to recover from.

You can find instructions for using the Recovery utility in the Rocket Yard guide:

Activation Lock Prevents Access to Your Mac

One of the features of newer Macs is the incorporation of T2 Security Chips, which provide a number of useful features, one of which is the ability to erase and deactivate your Mac if it is stolen.

Find My app shown on iOS device.
The Find My app (here shown on an iOS device) can be used to fix an unexpected activation lock on your Mac.

During beta testing, a few people reported that Catalina was failing to complete the installation because it believed the Mac had the activation lock set as if it had been reported stolen. Although I expect this issue to be resolved before macOS Catalina is fully released, if you do come across the issue, here’s how to fix it.

You can correct this issue by using another Mac or iOS device and launching the Find My Mac app, or opening a browser and going to the iCloud.com website. Log in to your iCloud account, if needed, then remove the Mac in question from being associated with your Apple ID.

This should allow you to restart the Mac and complete the Catalina installation.

Unable to Install Catalina on an External Drive

This issue can occur because of the T2 Security Chip found in recent vintage Macs. The T2 chip protects your Mac by default from being booted from an external device. This prevents someone from walking up to your Mac with a USB flash drive, booting your Mac, and accessing your files.

The default settings will also prevent you from installing Catalina on an external drive.

You can find out more about the T2 Security Chip and how to use the Startup Security Utility to configure external boot options in the Rocket Yard guide:

Miscellaneous Fixes for Install Problems

If the install issue you’re having isn’t covered in this guide there are always a few general-purpose tips that may help resolve the problem:

Startup Disk: Occasionally, the startup disk isn’t set or is set incorrectly. In the case of not being set, your Mac may take a very long time to start up as it searches for a device to use to start up from. It may also choose the wrong device to boot from, leaving you wondering what’s going on.

Startup Disk preference pane.
Use the Startup Disk preference pane to ensure your Mac is starting from the correct disk.

This behavior can explain one problem I’ve seen reported: a Mac that seems to complete a clean install but when the Mac finally reboots, it’s back to the original version of the OS, with no changes. In actuality, the clean install was performed, the Mac is just booting from the wrong startup device.

The fix is to open the Startup Disk preference pane and set the startup disk correctly for your Mac.

Reset NVRAM and SMC: The NVRAM and SMC hold information used by your Mac during startup. If either becomes corrupt, it can cause unusual effects on your Mac. Although resetting the NVRAM and SMC are considered a last-ditch effort to correct a problem, you should still try it because it does work from time to time.

You can find instructions in the guide:

Did You Have Any Catalina Install Issues?

This is our preliminary list of Catalina installation issues you may come across. But as more people perform the upgrade to Catalina, it won’t be surprising to see a few more issues become common.

With that in mind, did you have any issues installing macOS Catalina, and if so, did you discover a fix for the problem?

Leave a comment below and let us all know.

UPDATE 10.15.19:

If all else fails with your Catalina install and you want to downgrade, check out our article, How to Downgrade from macOS Catalina to Mojave or Earlier.

UPDATE 10.30.19:

If you need to transfer information from a previous version of the Mac OS, take a look at the Rocket Yard guide: How to Use Migration Assistant with macOS Catalina.

Tom Nelson
the authorTom Nelson
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  • Was having issue with supported Mac on external drive via USB hub, the installer was allowing installation to the external drive but keep back to internal drive after reboot.. plug the external drive directly to the Mac solve the issue

  • Hello,

    I had to wipe my 15” mid-2012 MacBook Pro, so it’s currently running Sierra 10.12.6. I’ve downloaded Catalina from the App Store, but I can’t get past the first page of the installer. I click continue and it just sits there with the continue button greyed out and never progresses to the next screen. I tried restarting my computer, but no luck.

  • Catalina would not install on 27 inch late 2012 running Mavericks. Tried stub installer from apple and full installer using patch app. Got full installer to run after starting in safe mode. Installer would then prompt for password, then off to the installation. Maybe it was a permissions thing, but who knows…

  • Since I reinstalled Catalina 10.10.5 because it wasn’t running the fan, I cannot download documents. I get an insufficient disk permissions, message. I have tried several fixes found on chat boards but nothing has worked.

  • Catalina would not install because of a memory issue with my Late 2015 iMac. I had to remove the 16GB of OWC RAM and then the OS was able to finish installing with just the 8GB of factory Apple RAM. I tried then reinstalling the OWC RAM, but Catalina is rejecting it (Computer won’t boot—gives beeping noise error). Any ideas?

    • Hi Geoff! There shouldn’t be an issue with the RAM, but the machine might need an SMC and PRAM reset after installing the RAM. Otherwise, if those don’t help, please reach out to our customer service department, the lifetime warranty on the RAM ensures that we will go ahead and get a new set to you!

      If you have any questions please contact us via one of the following methods:

      Phone 1-800-275-4576 or +1-815-338-8685
      Customer Service/Sales & Technical Support – Monday-Friday (8am-8pm CT) – Saturday & Sunday (Closed)

      Live Chat Technical Support – Monday-Friday (8am-8pm CT) – Saturday (9am-5pm CT) – Sunday (Closed)

      Live Chat Customer Service/Sales – Monday-Friday (7am-10pm CT) – Saturday & Sunday (9am-5pm CT)

  • Hi I am trying to download the MacOS Catalina on a MacBookAir early 2014 Yosemite 10.10.5 and when I click continue to install it a caution sign pops up at the top of my screen saying Downloading installer information to the target volume failed.Any help please. Stay safe

  • I’m trying to install to Catalina 10.15.6. I download the file and start the installer. But when it gets to choosing the HD to put it on, I get a yellow caution sign and it says, “macOS Catalina 10.15.6 Update can’t be installed on this disk. The volume does not meet the requirements for this update.”. I have plenty of space on there(over 700GB on a TB HD). So what is causing the problem?

  • I am trying to upgrade from Mojave to Catalina on Mac Air early 2015, I received an error from the Catalina installer that this upgrade requires a firmware update. I am on APFS. Does anyone know a solution for this issue.

    Stay Safe

  • I have MacBookAir mid 2013. So I tried the installation of macOS Catalina. I was upgrading from Mojave 10.14.6 to catalina from the system preferences. The download failed halfway giving me a network error. And every time I try to redownload it from the beginning it has been giving me this error. And also i had some 30+ GB free space on my hdd. But the downloads been eating my disc space, and now i only have 15GB free space. I don’t know where the downloaded files are at. Been bothering me a lot. I would appreciate some help

  • I have a MacBook Air 13″ Early 2015 with MacOS Majave 10.14.6.

    I get the following message when trying to install MacOS Catalina – any ideas?

    “you must be running macos catalina 10.15 or later to install on this volume”

  • I am trying to upgrade to Catalina from OS X 10.9.5
    I get as far as the install screen that shows Catalina will be installed in disk “Macintosh HD” and the back / install. I clicked Install, and then nothing happens. I waited a few hours and still nothing has happened.
    If anyone has any idea of what is happening or what I should do it would be appreciated! Thanks!

  • I am trying to upgrade to Catalina from Maverick.

    I get as far as the install screen that shows disk “Macintosh HD” and the back / install buttons below.

    When clicking install nothing happens but it goes gray. I waited overnight but still nothing.

    If anyone has a suggestion I would GREATLY appreciate! Thanks!

  • I’m using a Mac Mini (late 2012) and I cannot upgrade to Catalina from Mojave. The install crashes.

    Ran disk utility and this came up…

    warning: apfs_num_other_fsobjects (74) is not valid (76)

  • The disk is ghosted and I cannot select it for install. I did run disk utility on it. The drive has two other partitions all ghosted

    • Yep! The entire program is a ghost and a real pain in the butt. I’m finding a way to go back to the OS that I had before I installed Cat.

    • Steve Jobs would have never let this update OS to get out without it actually working. It’s the worst nightmare Apple has ever come up with.

  • While updating from system update installer when upgrading from 10.15.1. getting this error. “Unable to verify startup disk” error and “Try again” does nothing while Startup disk selection lead to restart to existing version.

    And downloaded the 10.15.3 from apple site and while trying installation from it, getting this error “mac OS 1o.15.3 update can not be installed on this disk. This volume does not meet the requirements for this update.”

    Please help.

  • I have a late 2012 i5 2.7 core iMac. I had an issue that my iMac just crashed n does not boot up. I tried all but nothing worked so erased all data n reinstalled Catalina however it gave error “ Mac OS cannot be installed on your on computer the installer resources master BOM were not found quit the installer to restart your computer . I am tired now n have tried all but won’t work pls help

  • After successful Catalina install on iMac, the “Catalina Install” folder, which is empty, keeps reappearing on my desktop.

    I can remove it by ejecting but, it reappears after shutting down and restarting my computer or when I awaken from computer sleep.

  • Hi,
    I am getting this error while upgrading to Catalina OS
    “you may not install to this volume because your home directory is in an incompatible location”
    Please advise how to fix.

  • Trying to install Catalina. It asks for my PW but the one I’m putting in is not working. How do I find my PW or make a new one?

  • Catalina failed to install on my late-2014 Mac Mini (128GB SSD + 1TB disk) with an error that include “Disk with a mount point is required”.

    Tried 3 times, then gave up. My hardware is probably too old to be supported by Catalina. Thankfully, I was able to return to High Sierra (10.13), which I’ll continue running until the Mac Mini runs no more.

  • I have a mid 2015 MacBook Pro 15 inch. I had to replace the SSD and did so with an ADATA SX8200PNP. I have downloaded the Catalina installer. I open it, click Continue, accept the license agreement, put in my password for the helper app etc. It does it’s think for about 13 minutes or so, goes to restarts, and restarts back in Mohave (10.14.6). Every time.

    Yes, my drive is formatted APFS according to Disk Utility.

    Is it my ADATA SX8200PNP SSD that is the issue?

    If so, what is the work around?


    • I had to replace an old SSD with a much newer Aura Pro X2
      Earlier models would not work. Call tech support and follow their recommendations.

      • I created an external USB bootable installer. Did the install from that. Up and running in about an hour.


  • I just tried to update my macbook pro and I got a warning screen at the end of the update. It said: The following disk images couldn’t be opened. macOSUpd10.15.14 corrupt image
    I’m not sure what this means or how to fix it. Please help.

    • In this case, the corrupt disk image is referring to the download of the mac OS Catalina installer which contains a disk image within it. While not common, it is not unusual that during a download of a large file such as the Catalina installer one or more files can become corrupt.

      The simple solution is to delete the “Install macOS Catalina: installer located in your /Application folder. Once it has been removed, you can re-download the installer from the Mac App store.


  • Hi
    I have a macbook pro which should support Catalina. But the two times I managed to complete download, my mac would just a long period of completion that would never end and the process would just abort so I had to start all over again.
    Most of the times the download wouldn’t even complete, because of so connection problems that do not really exist.
    What should I do to update my OS?

  • It won’t load on my 2012 Mac but acts like it is. Upon starting, the screen pops up like its continuing to download the software but it isn’t really, and I have no way to override it. I can’t get past the faux download to my desktop. I’ve tried numerous ways to escape and/or shut it down, but it comes right back to the download as before and I can’t get rid of it or into my laptop!

  • New update, has been downloaded and says needs to restart, when select restart it closes down and then the install black screen with white logo and loading bar comes up and gets to about 5%, then goes blank before coming back on again then starting up as if from the power off, and once on shows no update has been installed, the software update page says needs to restart to install, been through the same process about 10 times

      • Was storage issue, even though enough storage was free (just) it would not update, when i freed up some more storage by transferring to an external drive it then updated

  • HI, I just upgraded the 1TB hard drive on my 27 in Mac (late 2013) to an 1 TB SSD drive. MacOS is version 10.15.3. Before the SSD drive was installed, I was able to easily access (and sync) the Documents & Downloads folders on the iMac from my Windows 10 laptop. Every time I try to access these two folders from the Windows 10 laptop now, I get an error message on the laptop stating that the folders are not accessible (don’t have permission). I spent over an hour with Apple Support and they were not able to fix the issue. These folders are indicated as shared folders and all permissions are set as read & write on the iMac but Windows 10 still cannot access them. Disk Utility indicates that there are no errors. It is interesting to note that I am able to access & sync other folders on the iMac (e.g., folders that I created on the iMac) but not these two system folders (and Desktop). Would you have any ideas how to fix this? Thank you and much appreciated.

  • Hello Tom,
    I tried to repair the macOS Catalina start up disk using disk utility. But when first time the first aid option failed then again run the first aid. Disk utility showed the overlapped extent allocation error. But I could not replace the damaged file. I did not have the backup, and I was to regain my system. I found some software for disk recovery like Stellar Data Recovery for Mac, DiskDrill Data Recovery and Pandora. I downloaded free version of stellar and disk drill. Luck by chance I recovered in first attempt by stellar.

    • Am glad to hear the app you downloaded was able to recover your information.

      I want to point out that the error your drive was producing will likely return in time. You should make sure you have a good backup system in place so you don’t have to relay on data recovery applications. Even the best data recovery system is not a guarantee of being able to successfully recover your data.

      You may also want to consider replacing the drive having issues before the errors happen again.

      You can find drive replacement options here:


  • I just played with my Mouse and it seems the battery was not making contact and that part is now working. I will continue with my catalina install and see if the rest is working OK. Thanks for the trouble. Ed