Fix Installation of Mac Operating System Couldn’t be Completed

Installation Mac operating system is a procedure that takes a lot of steps and there can be many errors in the process that could stop the installation.

When you get any one of the following errors your installation stops or halts.

mac operating system
  • The pat /System/Installation/Packages/OSInstall.mpkg appears to be missing or damaged.
  • An error occurred installing macOS.
  • Unable to unmount volume for repair.
  • The storage system verifies or repair failed.
  • An error occurred while verifying firmware.

The most common error that flashes on the screen is couldn’t finish the installation.

Let us see how to fix this error

Generally, the installation log will support you for helping you with this issue and then you have saved the log and restart it and start the installation.

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Firstly, start off by opening mac in safe mode. Safe mode or safe boot is a method to start up your Mac so that it performs certain checks and prevents some software from automatically loading or opening. This mode helps you from external errors which disturb the process.

Follow these simple steps for this to happen:

  • Restart your Mac.
  • Once it starts to restart, hold the Shift key.
  • Leave it after you see the Apple logo. This enters your mac to in safe which means it is a better model for your OS to be updated in.

After doing this install the mac without no problem and error in installation

You can even start off startup manager which allows using a disk for a better installation and update.

Simply restarting can cause the error again. Now,  try with a start-up manager and follow these steps.

  • Turn off your Mac
  • Immediately after turning on your Mac, press and hold the Option (alt) key
  • You will see the Startup Manager popup, now you can release the Option key
  • Select your regular/standard (usually Macintosh HD) disk and click the arrow icon under it and hit Enter.

Repair Your Disk

If you are still having this issue, try repairing your disk. Here is how:

  • Restart your Mac, and while your computer restarting, immediately press and hold the Command and R keys until you see the Apple logo, then you can release the keys.
  • macOS Utilities will launch
  • Select Disk Utility and click Continue
  • Run First Aid.
  • If First Aid says the Disk is OK, then, on your computer, go to System Preferences
  • Then click on Users & Groups
  • And click the Login Items tab,

Now restart again and install the mac operating system

There are some other methods by which we can fix this error of not completely installing the mac operating system.

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All Macs running macOS Sierra, just as before, start by making sure your Mac is compatible with the macOS version you’re installing.

Date and time do matter for the installation of the operating system of mac. 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 the installation of a new version of the macOS.

For this, follow the procedure given below:

  • 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.

Now, restart and do the installation again and see.

Fix Mac Operating System couldn’t be completed issue by Installing Mac Operating System

The latest solution which cures most of the issues is to restore the backup. If you use Time Machine to regularly back up your Mac, you can try going back to an earlier state to see if it’s more compatible with the installer.

  • Make sure your backup drive is attached, then restart your computer and hold Command+R until the Apple logo appears. Instead of going to the Desktop, your computer will prompt you to choose the main language, then open a window called macOS Utilities.
  • In macOS Utilities, click “Restore from Time Machine Backup”, then click “Continue”.
  • There will be a screen displayed which is indicated with some information about what you’re about to do. Click “Continue” to complete the process.
  • Choose the drive you store your backups to and click Continue again, which will take you to a screen where you can choose your most recent backup. Afterward, click Continue again.
  • Now, your computer will restore the earlier backup.
  • Again, restart and check the installation process.

These are the ways with which we can fix the installation not completed of mac operating system.