007 First Light Disconnected From Server / Connection Lost Mid-Match Fix

What is the 007 First Light disconnection error?

This article covers the specific failure mode where 007 First Light connects successfully and starts a match, then drops you back to the main menu mid-mission with a "Disconnected from server" or "Connection lost — returning to title screen" message. This is distinct from the "cannot connect to server" failure on initial sign-in — if your problem is that you never get past the title screen, see our [multiplayer connection error guide](/en/errors/007-first-light-multiplayer-connection-error-online-fix) instead.

The mid-match drop is overwhelmingly a NAT/port/keepalive issue on the user's network side. The IO Interactive backend uses persistent UDP sessions on port 3074 with a 90-second keepalive — when a consumer router's NAT table evicts that mapping early, the next inbound packet hits a closed pinhole and the client times out.

When does it occur?

• 3–10 minutes into any multiplayer mission, repeatedly.
• Immediately after a checkpoint save (the game pings the backend to commit progress).
• When switching from co-op to a solo mission and back.
• After Windows Defender Firewall flips your network from "Private" to "Public."
• When your ISP performs CGNAT (Carrier-Grade NAT) — common on mobile broadband and some EU ISPs.
• After leaving the game idle in the menu for 4+ minutes.

Common causes

• NAT type set to Strict / Type 3 — UDP keepalive can't traverse the router cleanly.
• Required port UDP 3074 not forwarded (and IO Interactive's secondary 27015–27050 range blocked).
• Carrier-Grade NAT (CGNAT) shared IP — common on mobile broadband and fiber from Orange, Bouygues, Sky, Vodafone.
• Wi-Fi power-saving disconnect on laptops (the Wi-Fi card drops the connection during fades).
• IPv6 mismatch — game prefers IPv6 but your router advertises a stale IPv6 prefix.
• QoS / Smart Queue Management on your router de-prioritizing game traffic.
• Anticheat session token expiring — forces a reauthentication that the match loop can't survive.
• Background bandwidth hog (Steam download, Windows Update, OneDrive sync).

Step-by-step fixes

1. Check the IO Interactive status page first. Visit ioi.dk/status (or the in-game News tab). If "007 First Light Online Services" shows any orange/red status, the issue is server-side and no client fix will help — wait it out.
2. Forward UDP port 3074 on your router. Sign in to your router (usually 192.168.1.1 or 192.168.0.1). Find Port Forwarding / NAT / Virtual Servers. Add a rule: External port 3074, Internal port 3074, Protocol UDP, Internal IP = your PC/console. Also forward UDP 27015–27050 if available. Reboot the router.
3. Set your NAT type to Open / Type 1. On PC: Windows Settings → Network → Properties → set network to Private. On PS5: Settings → Network → Test Internet Connection → check NAT Type. On Xbox: Settings → General → Network settings → Test NAT type. If "Strict" or "Type 3", enable UPnP on your router (Advanced → UPnP → On).
4. Disable IPv6 for the game session. Windows: Settings → Network → Properties → Edit IP settings → uncheck IPv6 in the adapter properties. Reconnect. If your ISP uses dual-stack, the game's IPv6 path is the common drop trigger.
5. Set 007 First Light's network priority high. Windows Task Manager → Details tab → right-click 007FirstLight.exe → Set priority → High. Then in your router QoS settings (often Advanced → QoS), add your PC's MAC address as Highest priority.
6. Switch to wired Ethernet, or fix Wi-Fi power saving. Device Manager → Network adapters → right-click your Wi-Fi adapter → Properties → Power Management → uncheck "Allow the computer to turn off this device to save power." Then Advanced → "Wireless Mode" → set to 802.11ac/ax only (not "Auto").
7. Manually pick a closer server region. Main menu → Settings → Network → Server Region → choose the geographically closest option (EU-West, EU-Central, NA-East, NA-West, Asia-Pacific). The auto-select sometimes routes via a hub 200+ ms away, which makes mid-match drops far more likely.
8. If you're behind CGNAT, request a public IPv4. Call your ISP (Orange Livebox, Bouygues Bbox, Sky, Vodafone) and ask for a "public IPv4 address" or "to be moved off CGNAT." Most ISPs will do this for free if you cite gaming. Alternatively, a wired tether to a phone hotspot will bypass CGNAT temporarily for testing.

If it still doesn't work

If you've forwarded ports, disabled IPv6, and you're still getting dropped, the next layer is the anticheat reauthentication loop. Open %LOCALAPPDATA%\007FirstLight\Saved\Logs\007FirstLight.log and search for EOS_NotConnected or Session token expired. If you see those entries clustering around your drop times, the Epic Online Services session is the failure point — uninstall Epic Online Services from Settings → Apps → Installed apps, then verify game files in Steam/EGS; the launcher will reinstall a clean copy. If you're on Steam Deck or running through Proton, set Proton GE 9-27 or newer in the game's Compatibility settings — older Proton builds have a known UDP socket leak that triggers this exact symptom. For ongoing issues, the IO Interactive support ticket form at ioi.dk/support is the fastest escalation path; include your router model and ISP in the ticket.