I just read:
it is only affecting the new macOS Sierra Installer? or it is affecting all the new installers for macOS High Sierra and Mojave?
Thanks
Came
How to Fix a Damaged macOS Installer
Creating a macOS installer on a bootable USB drive provides a convenient way of installing a fresh copy of macOS on multiple Macs, and also allows you to perform a clean installation quickly and easily. If you tried to run your installer recently and unexpectedly received an error that it is...
forums.macrumors.com
The createinstallmedia command will fail with the new Sierra installer. Some code is munged somewhere. As a workaround, do an actual installation to your flash drive, then just copy the new installer to that drive's Applications folder. At least you can boot and get Sierra installed to an otherwise unbootable drive (or reinstalled over an earlier installation nondestructively).
it is only affecting the new macOS Sierra Installer? or it is affecting all the new installers for macOS High Sierra and Mojave?
Thanks
Came