First, make sure the dmg file you downloaded is valid. I managed to create two bootable USB from macOS Mojave and Catalina DMG file and successfully installed them on respect Mac. For those who failed to create bootable USB with TransMac, take a look at UUByte DMG Editor. Even if the Mac system uses Mac OS, you can still run Windows on it this way. If you have a Mac system but want to run Windows on that system, you will need to create Windows 10 bootable USB on Mac for PC. How To Create A Bootable Usb On Mac Osx.
