BLZBNTBNA00000005

The Battle.net desktop app failed to communicate with the Battle.net Update Agent, which is required to install, update, launch, and uninstall Blizzard games.

1. Update your drivers to resolve any compatibility issues.
2. Run a security scan to remove any viruses or malware infections.
3. Configure your security software's exception list to allow Blizzard applications to run.
4. Create a new administrator account to resolve permissions issues.
5. Uninstalling and reinstalling the Battle.net App may resolve rare launcher issues.