Quick answer: Check Activision service status, restart the PC rather than shutting it down, power-cycle the router, and test Ethernet. Remove a VPN or proxy, update the game, and return network settings to automatic. Flush the DNS cache or test a known public resolver only if service-name resolution is the suspected failure.
Before you start
- Open Activision Online Services and check the selected platform.
- Ask whether party members were disconnected at the same time.
- Pause large downloads and cloud synchronization.
- Write down any manual IP or DNS values before changing them.
How to fix Lost Connection to Host / Server Timed Out
- Restart Windows. Select Start > Power > Restart. The video correctly emphasizes Restart because it reloads network drivers and services more reliably than a Fast Startup shutdown.
- Restart the network in order. Unplug modem and router for about 30 seconds. Reconnect the modem, wait for its online light, then reconnect the router and start the PC.
- Use Ethernet for a test. A direct cable rules out Wi-Fi interference and roaming. If wired play is stable, repair the wireless link rather than the game installation.
- Disconnect VPNs and proxies. A VPN can add latency, change matchmaking region, or drop UDP traffic. Close it fully and test a normal ISP route.
- Update BO6 and Windows. Finish game updates in the launcher, install Windows updates, and use the PC or adapter manufacturer’s current network driver.
- Return IP settings to automatic. Open Settings > Network & internet > Advanced network settings > More network adapter options. Open the active adapter’s IPv4 properties and use automatic IP unless the network administrator supplied static values.
- Flush the DNS cache. Open Command Prompt or Terminal as administrator and run
ipconfig /flushdns. Microsoft says this discards negative and dynamically added resolver-cache entries. - Optionally test alternate DNS. Use Cloudflare 1.1.1.1 and 1.0.0.1 only as a resolver test. One viewer reported that returning to Automatic helped instead, so keep whichever setting is stable on the actual network.
- Allow the game through security software. Keep Windows Firewall enabled and allow the official Call of Duty executable and launcher. Remove duplicate or stale entries instead of disabling protection.
- Test a clean session. Close overlays, packet filters, traffic shapers, and background downloads, then play one match outside a party to isolate the failing layer.
Why this works
The message means the session stopped receiving a usable response before its timeout. A service outage, unstable Wi-Fi, congested router, VPN path, firewall rule, stale resolver entry, or local network driver can all break the session. The steps move from server-side checks to local isolation without changing undocumented ports or registry values.
If only parties fail
- Let a different player host the party.
- Confirm all players have the same current game version.
- Test without crossplay for one match, then restore the preferred setting.
- Have every party member restart after a playlist update.
Alternatives
- Test a phone hotspot briefly to compare the ISP route.
- Replace the Ethernet cable or change the router port.
- Check the router log for WAN reconnects at the exact disconnect time.
- For a general sign-in failure, use our BO6 unable-to-connect guide.
Warnings
Do not permanently disable the firewall or antivirus. Do not enter random MTU or port-forwarding values. DNS is not a cure for packet loss, and using a public resolver can be worse on some ISP networks.
Frequently asked questions
Does flushing DNS improve ping?
No. It clears cached name-resolution records. It may fix a bad lookup but does not shorten the gameplay route.
Why does Restart help when Shut down does not?
Windows Fast Startup can preserve part of the previous system session during shutdown. Restart reloads drivers and services.
Is this always my internet?
No. If many players disconnect together or Activision reports an incident, wait for the service to recover.
Official references
Source video
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