Why Is My Mac Fighting This Upgrade?

If you’re having trouble upgrading your Mac, first check whether your system is several macOS versions behind. Trying to skip multiple versions at once is often the problem.

Try upgrading in stages:

• Find your current macOS version.
• Look up the macOS versions in order, starting from the one you have.
• Upgrade one version at a time, starting with the next available macOS release.

If the upgrade still fails, try these additional steps:

• Check available storage
• Run First Aid in Disk Utility
• Delete the downloaded installer
• Verify the date and time settings
• Try install in Safe Mode