BLZBNTAGT0000084B

The Battle.net Update Agent couldn't modify necessary files on your hard drive. This usually happens when the required files are locked or in use by another program. Follow the steps below to resolve the issue.

1. Configure your security software's exception list to allow Blizzard applications to run.
2. Try creating a new administrator account to resolve permissions issues.
3. Run a security scan to remove any viruses or malware infections.
4. Uninstalling and reinstalling the Battle.net App may resolve rare launcher issues.
5. If the problem persists, uninstall and reinstall the game.