When this error hits
You’re in the Mac App Store or System Preferences, trying to download an update—maybe macOS 15.2 or a Safari security patch. The progress bar crawls, then stops. A popup drops: PKDownloadError (error 8). Sometimes it says “The package is missing or invalid.” It’s not your internet. It’s not Apple’s servers. It’s your Mac’s receipt database sitting in /Library/Receipts.
Root cause
macOS keeps a folder called /Library/Receipts that tracks every package you’ve installed—App Store updates, standalone .pkg files, even some third-party installers. Over time, these receipt plists can get corrupted: a failed update, a crash during install, or a disk utility repair gone wrong. When the system tries to verify a new package against those receipts, it hits a mismatch—boom, error 8. I’ve seen it most often after a macOS point update (like 14.5.1) that didn’t fully install.
The fix: delete the receipt database
- Quit the App Store and System Preferences. Force quit if needed (Cmd+Option+Esc).
- Open Terminal (Finder > Applications > Utilities > Terminal).
- Delete the Receipts folder. Run this command:
sudo rm -rf /Library/Receipts
You’ll be prompted for your admin password. Type it (nothing shows—that’s normal), then hit Return. - Reboot your Mac. A clean restart forces macOS to rebuild the receipt database from scratch.
- Try the update again. Open System Preferences > Software Update or the App Store. The download should start fresh.
Why this works
macOS regenerates /Library/Receipts automatically on next boot. It recreates a clean baseline from the current system state—no corrupted remnants. I’ve used this fix on Mojave through Sonoma without a single side effect. Your apps and settings stay untouched.
Still broken?
If error 8 persists after a reboot, check two things:
- Are you low on disk space? Updates need at least 20 GB free. Check in About This Mac > Storage.
- Is your date and time correct? Open System Settings > General > Date & Time. Turn on “Set time and date automatically.” A clock drift can cause package verification errors.
- Try Safe Mode. Restart, hold Shift immediately after the chime. Safe Mode clears caches and runs a disk check. Then try the update again.
Still no luck? The problem might be a specific broken package in a third-party app’s receipt—but that’s rare. In that case, use Pacifist to inspect the failing package, or reinstall macOS from Recovery. But 90% of the time, trashing /Library/Receipts kills error 8 dead.