This error occurs when the Battle.net Update Agent can't start due to missing or corrupted data. The Battle.net Update Agent is the program that launches, updates, and installs your Blizzard games.
- Delete the Battle.net Tools folder to have the Battle.net Update Agent automatically re-create necessary files.
- Update or reinstall Adobe Flash Player.
- Make sure Windows' Secondary Logon is enabled, which the Battle.net Update Agent requires in order to run correctly.
- Programs running in the background can conflict with the Battle.net Update Agent. Try closing background applications.
- Security software can interfere with the Battle.net Update Agent and prevent it from running properly. Disable or temporarily uninstall any security programs.
- If the issue persists, uninstall the game and download a new copy of the game installer from the Battle.net Game Downloads page.
Tried everything here?
If you have tried all of these steps and still require assistance, please visit our Technical Support Forum (World of Warcraft) (StarCraft II) (Diablo III) (Hearthstone) (Heroes of the Storm) (Overwatch) or contact us.