Why can't I download High Sierra? The file is always corrupted?

For some reason, the App Store never worked for me. I had to go here --> https://support.apple.com/en-ca/HT208969, then click on the High Sierra App Store link in step 4 to get a good copy. Be sure to delete the old copy before reinstalling.

Delete the "Install macOS High Sierra" app from the "Applications" folder and empty the Trash. Then try downloading the installer from the App Store again.

If this still doesn't help, then run Disk Utility First Aid on your drive and reboot the computer after deleting the corrupted installer again.

If the App Store says ‘Open’ then it is detecting a previous download of the install app

go to the Applications folder locate Install macOS High Sierra.app.

Move it to the Trash, empty the Trash.

Connect your mac to your router via cable.

Restart, click on the link again, the App Store should say ‘Get' or 'Download'.

Do not use the mac while it is downloading or any other devices that share the same

internet connection.