macOS could not be downloaded.
Make sure you're connected to the internet and try again, or contact Apple
support for assistance.
An error occurred while downloading the selected updates. Please check your
internet connection and try again.
If an error occurred while updating or installing macOS
The message might say that an error occurred while downloading, preparing, or installing, or that the software is damaged, could not be verified, failed to personalize, or needs to be reinstalled. The cause of such messages can vary, and sometimes they're only temporary. Try these solutions.
Check storage space
If the message says that your Mac doesn't have enough storage space, free up storage space.
Check your internet connection
The installer needs a stable internet connection to download macOS and get firmware and other information specific to your Mac model. Make sure that your Mac is connected to the internet.
Install from macOS Recovery
To ensure that no other software on your Mac can interfere with installation, install macOS from macOS Recovery.
For the same reason, if you’re installing via the App Store or Software Update instead of Recovery, it might help to start up in safe mode before installing.
Repair your startup disk
Use Disk Utility to repair your startup disk from macOS Recovery. (If you just used Disk Utility to erase your startup disk, it’s not necessary to also repair it.)
If you’re using a previously downloaded installer that your Mac says is damaged or can’t be verified, delete it and download the installer from Apple after repairing your disk.
Revive or restore Mac firmware
Rarely, if using a Mac with Apple silicon or Apple T2 Security Chip, you might need to revive or restore Mac firmware to resolve a persistent macOS installation issue.
