Update corrupted the game

Installed the most recent update and when I go to launch it says the file, "“Command & Conquer™: Generals Deluxe Edition” is damaged and can’t be opened. Delete “Command & Conquer™: Generals Deluxe Edition” and download it again from the App Store.” How do re-download it from the App Store when the App Store only allows me to “Open?"

Gary-8829 about Command & Conquer™: Generals Deluxe Edition