To create a bootable installer, these files must be available from within the installer directory, to be copied from there. The bulk of the downloaded files is put directly in an auxiliary directory in the root of the volume you selected in the installer. Rather select Quit from the application menu at the top of the screen.
When you get to the final screen, do NOT click the Reset button, but Then it will start downloading the full version. If you got the stub, then you must run the program, accept the license and pick a target volume. It can appear random which systems that receive the full installation package and which only get the stub. On some systems, only a small stub of about 19MB is downloaded. This will create a directory called 'Install macOS High Sierra' under Applications. First, you must download the High Sierra package from the Mac App Store.
