BLZBNTAGT00000840

Updated: 1 week ago
Article ID: 23418

Common Problems

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Error Code: BLZBNTAGT00000840

The Blizzard 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. Restart your computer to resolve problems caused by programs and services running in the background.
  2. Run the repair tool to repair any damaged game files.
  3. Disable or temporarily uninstall any security programs, which may mistakenly identify the login module as a security threat.
  4. Close all other applications to resolve software conflicts and free up resources.
  5. Run the Blizzard Battle.net Desktop App in Administrator Mode to address many installation, patching, networking, and start-up errors.
Advanced Troubleshooting
  1. Delete the Battle.net Tools folder to automatically rebuild outdated or corrupt files.
  2. Try creating a new administrator account to resolve permissions issues.
  3. Run ScanDisk and defragment your hard drive to try to repair any bad sectors.
    Note: Do not defragment a Solid State Drive (SSD).
  1. Restart your computer to resolve problems caused by programs and services running in the background.
  2. Run the repair tool to repair any damaged game files.
  3. Disable or temporarily uninstall any security programs, which may mistakenly identify the login module as a security threat.
  4. Close all other applications to resolve software conflicts and free up resources.
  5. Run the Blizzard Battle.net Desktop App in Administrator Mode to address many installation, patching, networking, and start-up errors.
Advanced Troubleshooting
  1. Delete the Battle.net Tools folder to automatically rebuild outdated or corrupt files.
  2. Try creating a new administrator account to resolve permissions issues.
  3. Repair Disk Permissions to resolve any permission conflicts with logon modules.

Tried everything here?

If you have tried these steps and still require assistance, visit our Technical Support Forums (World of Warcraft) (StarCraft II) (Diablo III) (Hearthstone) (Heroes of the Storm) (Overwatch) or contact us.