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Reply To: [Solved] MacBook Pro 14″ M3 encountering macOS Installer Error: ‘An error occurred preparing software update’ after update (macOS Sequoia 15.1)
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Home › Forums › OS Updates, Recovery & Error Codes › [Solved] MacBook Pro 14″ M3 encountering macOS Installer Error: ‘An error occurred preparing software update’ after update (macOS Sequoia 15.1) › Reply To: [Solved] MacBook Pro 14″ M3 encountering macOS Installer Error: ‘An error occurred preparing software update’ after update (macOS Sequoia 15.1)
Jeffrey BurnsClearing corrupted delta update caches, downloading full standalone installer, and running startosinstall.
Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:
- Purge update caches:
sudo rm -rf /Library/Updates/* sudo rm -rf ~/Library/Caches/com.apple.SoftwareUpdate/* - Download full installer:
softwareupdate --fetch-full-installer --full-installer-version 15.1. - Execute terminal installer:
sudo /Applications/Install macOS Sequoia.app/Contents/Resources/startosinstall --agreetolicense --forcequitapps.
Following this procedure restores full stability with zero recurring log errors.