If you are receiving this error while attempting to install Diablo® II, Diablo® II: Lord of Destruction, or StarCraft® with game discs, this means the version that is located on the discs are Classic Environment application installs. These will not install on more recent Mac OS X versions.
If you have a newer Mac that is Intel-based or is above Mac OS X 10.5, you need a digital version of the game. You can add your CD keys to your Blizzard account to download the game client. If you've lost your CD key, you'll need to purchase a new copy of the game from the Blizzard Shop.
Note: The CD key needed for the digital download will be 26 characters in length. You can register an older 13 digit StarCraft CD key or 16 digit Diablo II CD key and it will automatically upgrade to the new 26 alphanumeric CD key required to install.