Hello, adamstr4!
Thank you for visiting the Apple Support Communities. If I understand correctly you are having some difficulties with updating your macOS. I know that keeping your OS up-to-date is vital, so I’m happy to help find a resolution.
Please make sure of the following:
- Disconnect any external hard rives, audio drives, or any other peripherals before trying to install the macOS update.
- If you have added third-party RAM, remove it before updating.
- Delete the old installer file, then download a fresh one: Find and delete files on your Mac
If you’ve completed those steps and still cannot install the update, then create a new user account on your Mac, and try to update from the new user. How to test an issue in another user account on your Mac
If the error still persists, use Disk Utility to repair your disk: Repair a storage device in Disk Utility on Mac
Please keep me posted on your progress.
Take care!