A Required Download Is Missing Mac Os X El Capitan

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These advanced steps are primarily for system administrators and others who are familiar with the command line. You don't need a bootable installer to upgrade macOS or reinstall macOS, but it can be useful when you want to install on multiple computers without downloading the installer each time.

Download macOS

Find the appropriate download link in the upgrade instructions for each macOS version:

MacOS Recovery makes it easy to reinstall the Mac operating system, even if you need to erase your startup disk first. All you need is a connection to the Internet. If a wireless network is available, you can choose it from the Wi-Fi menu, which is also available in macOS Recovery. Outline: OS X El Capitan: The Missing Manual is divided into six parts, each containing several chapters: Part One: The OS X Desktop covers everything you see on the screen when you turn on an OS X computer: folders, windows, icons, the Dock, the Sidebar, Spotlight, Dashboard, Spaces, Mission Control, Launchpad, Time Machine, menus, scroll bars, the Trash, aliases, the a menu, and so on.

macOS Catalina, macOS Mojave, ormacOS High Sierra
Installers for each of these macOS versions download directly to your Applications folder as an app named Install macOS Catalina, Install macOS Mojave, or Install macOS High Sierra. If the installer opens after downloading, quit it without continuing installation. Important: To get the correct installer, download from a Mac that is using macOS Sierra 10.12.5 or later, or El Capitan 10.11.6. Enterprise administrators, please download from Apple, not a locally hosted software-update server.

OS X El Capitan
El Capitan downloads as a disk image. On a Mac that is compatible with El Capitan, open the disk image and run the installer within, named InstallMacOSX.pkg. It installs an app named Install OS X El Capitan into your Applications folder. You will create the bootable installer from this app, not from the disk image or .pkg installer.

Use the 'createinstallmedia' command in Terminal

  1. Connect the USB flash drive or other volume that you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.
  2. Open Terminal, which is in the Utilities folder of your Applications folder.
  3. Type or paste one of the following commands in Terminal. These assume that the installer is still in your Applications folder, and MyVolume is the name of the USB flash drive or other volume you're using. If it has a different name, replace MyVolume in these commands with the name of your volume.
    Catalina:*
    Mojave:*

    High Sierra:*
    El Capitan:
  4. Press Return after typing the command.
  5. When prompted, type your administrator password and press Return again. Terminal doesn't show any characters as you type your password.
  6. When prompted, type Y to confirm that you want to erase the volume, then press Return. Terminal shows the progress as the bootable installer is created.
  7. When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as Install macOS Catalina. You can now quit Terminal and eject the volume.

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument, similar to the way this argument is used in the command for El Capitan.

Use the bootable installer

After creating the bootable installer, follow these steps to use it:

  1. Plug the bootable installer into a compatible Mac.
  2. Use Startup Manager or Startup Disk preferences to select the bootable installer as the startup disk, then start up from it. Your Mac will start up to macOS Recovery.
    Learn about selecting a startup disk, including what to do if your Mac doesn't start up from it.
  3. Choose your language, if prompted.
  4. A bootable installer doesn't download macOS from the Internet, but it does require the Internet to get information specific to your Mac model, such as firmware updates. If you need to connect to a Wi-Fi network, use the Wi-Fi menu in the menu bar.
  5. Select Install macOS (or Install OS X) from the Utilities window, then click Continue and follow the onscreen instructions.

Learn more

A Required Download Is Missing Mac Os X El Capitan 10 11 6

For more information about the createinstallmedia command and the arguments that you can use with it, make sure that the macOS installer is in your Applications folder, then enter this path in Terminal:

Catalina:

Mojave:

High Sierra:

El Capitan:

macOS Catalina gives you more of everything you love about Mac. Experience music, TV, and podcasts in three all-new Mac apps. Enjoy your favorite iPad apps now on your Mac. Extend your workspace and expand your creativity with iPad and Apple Pencil. And discover smart new features in the apps you use every day. Now you can take everything you do above and beyond.

Check compatibility

If you're using one of these computers with OS X Mavericks or later,* you can install macOS Catalina. Your Mac also needs at least 4GB of memory and 12.5GB of available storage space, or up to 18.5GB of storage space when upgrading from OS X Yosemite or earlier.

MacBook introduced in 2015 or later
MacBook Air introduced in 2012 or later
MacBook Pro introduced in 2012 or later
Mac mini introduced in 2012 or later
iMac introduced in 2012 or later
iMac Pro (all models)
Mac Pro introduced in 2013 or later

* To upgrade from Lion or Mountain Lion, first upgrade to El Capitan, then upgrade to Catalina. To find your macOS version, Mac model, memory, and storage space, choose About This Mac from the Apple menu . If your Mac isn't compatible with macOS Catalina, the installer will let you know. View the complete list of compatible computers.

Make a backup

A Required Download Is Missing Mac Os X El Capitan Dmg

Before installing any upgrade, it’s a good idea to back up your Mac. Time Machine makes it simple, and other backup methods are also available. Learn how to back up your Mac.

Get connected

It takes time to download and install macOS, so make sure that you have a reliable Internet connection. If you're using a Mac notebook computer, plug it into AC power.

Download macOS Catalina

If you're using macOS Mojave, get macOS Catalina via Software Update: Choose Apple menu  > System Preferences, then click Software Update.

Or use this link to open the macOS Catalina page on the App Store: Get macOS Catalina. Then click the Get button or iCloud download icon.

Begin installation

After downloading, the installer opens automatically.

Click Continue and follow the onscreen instructions. You might find it easiest to begin installation in the evening so that it can complete overnight, if needed.

Capitan

If the installer asks for permission to install a helper tool, enter the administrator name and password that you use to log in to your Mac, then click Add Helper.

Allow installation to complete

Please allow installation to complete without putting your Mac to sleep or closing its lid. Your Mac might restart, show a progress bar, or show a blank screen several times as it installs both macOS and related updates to your Mac firmware.

Stay up to date

After installing macOS Catalina, you will be notified when updates to macOS Catalina are available. You can also use Software Update to check for updates: Choose Apple menu  > System Preferences, then click Software Update.

Or get macOS Catalina automatically

If you're using OS X El Capitan v10.11.5 or later and your App Store preferences or Software Update preferences are set to download new updates when available, macOS Catalina will download conveniently in the background, making it even easier to upgrade. A notification will inform you when macOS Catalina is ready to be installed. Click Install to get started, or dismiss the notification to install later. When you're ready to install, just open the file named Install macOS Catalina from your Applications folder.

Learn more

  • If the installer shows a list of apps that are not optimized for your Mac, learn about 32-bit app compatibility, then choose whether to proceed with the installation.
  • For the strongest security and latest features, upgrade to macOS Catalina. If you have hardware or software that isn't compatible with Catalina, you might be able to install an earlier macOS, such as Mojave, High Sierra, Sierra, or El Capitan.
  • You can also use macOS Recovery to reinstall macOS.