This error means Battle.net Agent (the process that installs and patches our games) couldn't stream necessary files.
Network folder installations of this game are no longer supported. Please move your game folder to a local drive, then try again.
Standalone patches are downloaded outside of the game launcher or the Battle.net desktop app.
Many common hard drive or OS problems on a Mac can be resolved by running Repair Disk.
The Battle.net Update Agent could not install in the specified folder location.
Your installation could not be started. Please try again.