Updated: 1 month ago
Article ID: 16531
Relevant Games:

Common Problems

Whoops! Looks like something broke (or crashed). Please try restarting the Blizzard desktop app and/or your computer.
Error Code: BLZBNTBNA00000005

The Blizzard desktop app failed to communicate with the Blizzard Update Agent, which is required to install, update, launch, and uninstall Blizzard games. Before attempting the troubleshooting steps below, leave the app to attempt to communicate with the Blizzard Update Agent for a few minutes.

  1. Restart your computer to resolve problems caused by programs and services running in the background.
  2. Update your drivers and operating system to resolve any compatibility issues.
  3. Delete the Tools folder to automatically rebuild outdated or corrupt files.
  4. Close all other applications to resolve software conflicts and free up resources.
Advanced Troubleshooting
  1. Download and run Microsoft's Program Install and Uninstall troubleshooter.
  2. Disable or temporarily uninstall any security programs, which may mistakenly identify the login module as a security threat.
  3. Run a security scan to remove any viruses or malware infections.
  4. Make sure Windows Secondary Logon is enabled, which Blizzard Agent requires to run correctly.
  5. Log files may help us troubleshoot this issue. To perform this step, shut down the Blizzard app, wait 60 seconds, then gather your Blizzard logs and send them to Use the subject line: [Your BattleTag Here] BLZBNTBNA00000005 and be sure to include any relevant information in the message’s body. If the issue persists, uninstall the Blizzard Desktop application and download a new copy from the Game Downloads page.

Tried everything here?

If the steps above did not resolve your problem, visit our Technical Support forum or contact us.