High Sierra Installer starts downloading something, finishes in less than a second, then fails to install
So I downloaded the High Sierra Installer and when I open it and try to start the install, it starts a download of something. Less than a second after I enter my password to start the install, it starts downloading something and finishes immediately. After this it prompts me to close everything and restart my computer but after I click 'Restart', it closes all of my open applications and then shows the error message "An error occurred while preparing the installation. Try running this application again.”. What can I do to fix this problem?
MacBook Air