Repairing disk errors or fixing a non-booting OS.
In the "Restore from" dropdown menu, select the mounted OS X DMG image.
This typically points to a corruption issue within the downloaded DMG file or an unstable USB drive connection. Try formatting the drive again, downloading a fresh copy of the DMG, or switching to a different USB port. create mac os x bootable usb installer from dmg
I should also provide a second method: extracting the .app from a DMG (if it's an installer package) and then using the standard createinstallmedia command. That covers both scenarios.
While Apple provides official methods using the createinstallmedia command (which typically requires an .app bundle), many advanced users, legacy system enthusiasts, or those working with custom macOS builds often find themselves starting with a file. This guide will walk you through every method, from the graphical interface to the command line, ensuring you can create a flawless bootable installer from almost any macOS DMG. Repairing disk errors or fixing a non-booting OS
sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app Use code with caution.
The USB drive must be formatted correctly to work as a bootable installer. Plug the USB drive into your Mac. Open (found in Applications/Utilities). Select your USB drive from the left sidebar. Click Erase in the top toolbar. Configure the following: Try formatting the drive again, downloading a fresh
After conversion, use the dd command with the resulting ISO or IMG file.