If you are hitting this error while trying to launch the VCSA Installer, “Installer” is damaged and can’t be opened. You should eject the disk image. This is most likely just macOS Security Gatekeeper getting in the way, don’t worry the fix is simple!
Note: This issue also affects the CLI Installer too.
To have the VCSA Installer bypass the macOS Security Gatekeeper, you need to recursively remove the metadata quarantine attribute “com.apple.quarantine” on the ISO/Disk Image.
First, make sure the disk image is unmounted, then open up Terminal and run the following command. Make sure you enter the full path to that ISO/Disk Image; the best way to do this is to drag and drop the file straight into the Terminal.
sudo xattr -r -d com.apple.quarantine <Full Path to ISO>
You will be prompted to enter your password.
That’s all you need to do. Mount the ISO/Disk Image again and you should be able to run the installer.
I hope you found this helpful. Feel free to comment if you have any questions.Follow @nmangraviti