This application has encountered a critical error: ERROR #1 Fatal Exception

Error 1 can occur when you have an unstable internet connection or when a third-party program prevents Battle.net Agent from patching, installing, or launching our games. Follow the steps below to troubleshoot the issue.

Windows

  1. Programs running in the background can cause problems when you try to launch a game. Try closing background applications.
  2. Outdated or corrupt Battle.net files may cause a game to crash or prevent a game from launching. Delete the Battle.net Tools folder. Battle.net Agent will automatically rebuild necessary files.
  3. Run the Battle.net repair tool to repair any damaged game files.
  4. Older driver versions may be incompatible with current versions of our games. Update your drivers.
  5. Battle.net Agent requires a stable connection to the internet. Try optimizing your internet connection.
Advanced Troubleshooting
  1. Malware and viruses can damage or block access to files the game needs to run. Run a security scan to fix any infections.
  2. Monitoring software, like Net Nanny, can interfere with the game's ability to access files on your computer. Try disabling or temporarily uninstalling your monitoring program, or contact the software manufacturer for help.
  3. An outdated version of Adobe Flash may cause Error 1. Update Flash in Internet Explorer, even if you normally use a different browser.

Mac

  1. Programs running in the background can cause problems when you try to launch a game. Try closing background applications.
  2. Outdated or corrupt Battle.net files may cause a game to crash or prevent a game from launching. Delete the Battle.net Tools folder. Battle.net Agent will automatically rebuild necessary files.
  3. Run the Battle.net repair tool to repair any damaged game files.
  4. Changes to your Mac's permissions may prevent the game from running. Try repairing your disk permissions.
  5. Battle.net Agent requires a stable connection to the internet. Try optimizing your internet connection.

Tried everything here?

If you tried all of the steps for your operating system and still require need assistance, please visit our Technical Support Forum (World of Warcraft) (StarCraft II) (Diablo III) (Hearthstone) (Heroes of the Storm) (Overwatch) or contact us.