macOS update failed with an error? 7 fixes to try

2 min read · 7 steps · Updated 2 October 2026

Short answer

Check that the internet connection is stable and that the Mac has enough free storage, then try the update again. If the error returns, install the update in safe mode. After that, repair the startup disk with Disk Utility in macOS Recovery and install macOS from there.

Error messages during a macOS update say, for example, that the software is damaged, could not be verified or needs to be reinstalled. Apple notes that the cause varies and that such messages are sometimes only temporary. So the first step is to try again.

Menu names are from recent versions of macOS, where the settings app is called System Settings.

Step by step

  1. Check the internet connection

    The installer needs a stable connection for the whole download. Move closer to the router or use a network cable, and avoid a phone hotspot for a large update.

  2. Free up storage

    If the message mentions space, the Mac does not have enough free storage for the update. Delete or move large files, then try again. How to find them: how to check and free up storage on a Mac.

  3. Install in safe mode

    Start the Mac in safe mode and run Software Update from there. In safe mode, other software cannot get in the way of the installer. See how to start a Mac in safe mode.

  4. Repair the startup disk

    Start from macOS Recovery, open Disk Utility, select the startup disk and click First Aid. On a Mac with Apple silicon, switch the Mac off, then press and hold the power button until the startup options appear, click Options and click Continue. On an Intel Mac, switch it on and at once hold Command and R.

  5. Delete the damaged installer

    If you downloaded an installer app such as Install macOS from the App Store, drag it from the Applications folder to the Bin after the repair and download it again.

  6. Install macOS from Recovery

    In macOS Recovery, choose Reinstall macOS. Nothing else is running there, so no other software can disturb the installation. Your files stay in place.

  7. Last resort: erase the Mac

    If every attempt fails, Apple's final option is to erase the Mac and set it up again. This deletes everything on it. Make sure you have a current backup before you do this.

Good to know

Before any large update, make a backup: how to back up a Mac with Time Machine.

An update that only seems to hang on the Apple logo is usually still working: Mac stuck on the Apple logo or loading bar.

The normal way to update is described in how to update macOS on your Mac.

In short: Stable internet, free storage, safe mode, First Aid, fresh installer, install from Recovery, erase only as a last resort.

Sources
  • Apple Support: If an error occurred while updating or installing macOS

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