I just got a new computer and can't activate, download or install Flash. I keep getting the message: “install_flash_player_osx-3.dmg” is damaged and can’t be opened. You should move it to the Trash." This happens no matter how I try to download and install, and whether it's Safari or Firefox. Currently have Mac OS High Sierra v.10.13. Thanks for any advice.
[moderator: edited title to summarize issue being reported]