What does Call of Duty Error Code 6 mean?

The short answer

Call of Duty error code 6 means the game lost its connection to the online servers, usually due to a network issue on your end or a server outage on Activision’s side.

Why does it happen?

This error typically shows up when you’re trying to join a match, load into a lobby, or while playing online. The most common causes are:

  • Activision servers are down — during updates, maintenance, or high-traffic periods, the servers can struggle to keep up
  • Unstable internet connection — packet loss, high latency, or a weak Wi-Fi signal can drop your connection mid-game
  • NAT type issues — a strict or moderate NAT type can make it harder for your console or PC to communicate with game servers
  • Corrupted game files — damaged or incomplete game data can cause connection handshakes to fail
  • Outdated game version — if you’re not running the latest update, the servers may reject your connection

How to fix it

Try these steps in order:

  1. Check server status — search “Activision server status” online to see if there’s an outage. If there is, you just have to wait
  2. Restart the game — close Call of Duty completely and relaunch it
  3. Restart your router — unplug it for 30 seconds, plug it back in, and wait for a full reconnection
  4. Use a wired connection — if you’re on Wi-Fi, plug in an Ethernet cable for a more stable connection
  5. Change your DNS — switch to Google DNS (8.8.8.8 and 8.8.4.4) or Cloudflare DNS (1.1.1.1) in your network settings
  6. Open your NAT type — enable UPnP on your router or forward the ports Call of Duty uses (you can find the specific ports on Activision’s support site)
  7. Verify game files — on PC, use Steam or Battle.net’s repair/verify feature. On console, try uninstalling and reinstalling the game

When should you worry?

This error is almost always fixable. But a few things to keep in mind:

  • If it happens every time you play, your ISP might be throttling gaming traffic or your router may need a firmware update
  • If only Call of Duty is affected, the issue is likely server-side or related to your NAT type rather than your whole internet
  • If the error started after an update, wait a day or two — post-update server instability is common and usually gets resolved quickly