Getting this error when reinstalling Diablo 2
Game data may have been altered or corrupted. We can no longer determine if you need to patch your game.
Run the Blizzard Battle.net desktop app in Administrator Mode to address many installation, patching, networking, and start-up errors.
Create a new administrator account to resolve permissions issues.
Reset Folder and File Permissions to make sure there is no conflict between the latest OS update and your permissions.