Battle.net Blizzard Error Code BLZBNTAGT00000005: How to Fix It

Easy 15-30 minutes Medium Severity Verified June 2026
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Error Code
BLZBNTAGT00000005
Brand
Battle.net Blizzard
Product Type
game_launcher
Severity
Medium
DIY Difficulty
Easy
Estimated Fix Time
15-30 minutes
Error BLZBNTAGT00000005 appears in the Battle.net desktop launcher when the application cannot establish or maintain a stable network connection to Blizzard's servers. This can prevent you from logging in, updating games, or launching titles like World of Warcraft, Overwatch 2, or Diablo IV. The error is almost always caused by a local network issue, firewall block, or corrupted launcher data — and can typically be resolved without contacting Blizzard support.
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Tools You'll Need

How to Fix Error Code BLZBNTAGT00000005

  1. Check Blizzard's Server Status

  2. Restart Your Router and Modem

  3. Run Battle.net as Administrator

  4. Flush DNS Cache and Reset Network Settings

    Running netsh winsock reset will reset all Winsock catalog entries. This is safe but requires a PC restart to take effect.

  5. Add Battle.net to Your Firewall and Antivirus Exceptions

    Do not permanently disable your firewall or antivirus. Only add exceptions for the specific Battle.net executables.

  6. Disable VPN or Proxy Connections

  7. Delete the Battle.net Cache Folder

    Do NOT delete the entire Battle.net ProgramData folder — only the 'Cache' subfolder. Deleting the wrong folder may remove important configuration data.

  8. Uninstall and Reinstall the Battle.net App

    Reinstalling Battle.net will not delete your installed games or saved settings tied to your account, but you will need to log in again.
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When to Call a Professional

If you have completed all steps and the error persists, contact Blizzard Support directly at us.battle.net/support and submit a ticket. Provide them with your MSInfo and DxDiag files (run 'msinfo32' and 'dxdiag' from the Windows Run dialog to generate these). You should also consider contacting your Internet Service Provider if the DNS reset and router restart did not resolve connectivity — your ISP may have a routing issue or port block affecting Blizzard's network.

Frequently Asked Questions

What does Battle.net error BLZBNTAGT00000005 mean?
This error means the Battle.net launcher's background agent (called the 'Battle.net Agent') failed to connect to Blizzard's servers. It is a network-level error that can be triggered by firewall blocks, corrupted cache data, a VPN, or an unstable internet connection.
Is BLZBNTAGT00000005 caused by Blizzard's servers being down?
It can be, but most of the time this error is caused by something on the local PC or home network side rather than a Blizzard outage. Always check Blizzard's official server status page first to rule out an outage before troubleshooting your own system.
Will deleting the Battle.net cache delete my games?
No. Your installed games (World of Warcraft, Overwatch 2, Diablo IV, etc.) are stored in a completely separate game directory and are not affected by deleting the Battle.net cache folder. Only temporary launcher files are removed.
Can a VPN cause error BLZBNTAGT00000005?
Yes. VPNs are one of the most common triggers for this error. The Battle.net Agent uses specific network ports and endpoints, and VPN routing can interfere with those connections or cause Blizzard's network to reject the traffic. Disable your VPN before launching Battle.net.
Which ports does Battle.net need to be open to avoid this error?
Blizzard recommends ensuring the following ports are open on your router and firewall: TCP ports 80, 443, 1119, and 3724; UDP ports 3478, 3479, 5060, 5062, and 6250. If you have a restrictive network or router firewall, ensure these ports are not blocked. Check your router's port forwarding or firewall settings if needed.

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