Battle.net Blizzard Error Code BLZBNTBNA00000005: How to Fix It

Easy 15-30 minutes Medium Severity Verified June 2026
Error Code
BLZBNTBNA00000005
Brand
Battle.net Blizzard
Product Type
game_launcher
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
15-30 minutes
Error code BLZBNTBNA00000005 means the Battle.net desktop app failed to download or apply an update to itself. This usually happens because of a network interruption, a permissions issue on your PC, or a corrupted update file blocking the process. The good news is that this is a software-level problem and can almost always be resolved at home without contacting support.
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Tools You'll Need

How to Fix Error Code BLZBNTBNA00000005

  1. Restart the Battle.net App Completely

  2. Run Battle.net as Administrator

    Only run trusted software as administrator. Do not do this with apps you did not install yourself.
  3. Check and Flush Your Internet Connection

    Resetting Winsock may temporarily affect other network programs. A restart will restore normal network behavior.
  4. Delete the Cached Battle.net Update Files

    Only delete folders inside the Battle.net directory, not the entire Battle.net installation folder. This will not delete your games.
  5. Temporarily Disable Antivirus or Firewall

    Never leave your antivirus or firewall disabled longer than necessary. Re-enable it as soon as the update completes.
  6. Add Battle.net as a Firewall Exception

  7. Repair or Reinstall the Battle.net App

    Download the installer only from the official Blizzard website to avoid malware. Do not delete your game directories (e.g., World of Warcraft, Overwatch) unless instructed — they are stored separately.
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When to Call a Professional

If you have completed all steps including a full reinstall and the error persists, contact Blizzard Entertainment customer support directly at support.battle.net. This may indicate a server-side issue with Blizzard's update delivery network, an account-specific problem, or a deeper Windows system corruption (such as damaged system files) that requires advanced repair using tools like 'sfc /scannow' or a Windows repair install. Blizzard support agents can also check if your account or region is experiencing a known outage.

Frequently Asked Questions

What does Battle.net error BLZBNTBNA00000005 mean?
It means the Battle.net desktop app was unable to download or apply an update to itself. This is different from a game update error — it specifically affects the launcher application. Common causes include network issues, Windows permission restrictions, security software interference, or corrupted cached update files.
Will fixing this error delete my games?
No. Even if you fully uninstall and reinstall the Battle.net app, your game files are stored in separate directories (such as C:\Program Files (x86)\World of Warcraft) and are not touched during the process. After reinstalling Battle.net, the app will detect your existing game installations automatically.
Why does Battle.net keep failing to update?
Repeated update failures are usually caused by one of three things: a persistent antivirus or firewall block on Battle.net's update files, a corrupted cache that keeps serving broken data, or insufficient Windows account permissions. Following the steps to clear the cache, add firewall exceptions, and run Battle.net as administrator resolves the majority of recurring cases.
Can I play my games while getting this error?
In some cases, existing games may still launch from within the Battle.net client even while the app itself fails to update. However, you may be missing security patches or stability improvements. It is strongly recommended to resolve the update error before extended gameplay, as some games may also have pending updates that are blocked by the same underlying issue.
Is BLZBNTBNA00000005 caused by a Blizzard server outage?
It can be, though it is less common. If the error appeared suddenly for many users at the same time, check Blizzard's official service status page at us.battle.net/support/en/article/76459 or follow @BlizzardCS on social media for outage announcements. If Blizzard's servers are down, there is nothing to fix on your end — simply wait for the outage to be resolved.