# Nuclear Option Server Troubleshooting (/docs/nuclear-option/troubleshooting)



import { Step, Steps } from 'fumadocs-ui/components/steps';

This guide covers the most common Nuclear Option server issues and how to fix them.

Required Ports [#required-ports]

| Port    | Protocol | Default | Purpose                      |
| ------- | -------- | ------- | ---------------------------- |
| Game    | UDP      | 7777    | Player connections           |
| Query   | UDP      | 7778    | Steam server browser         |
| Command | TCP      | 7779    | Remote commands (if enabled) |

On XGamingServer, ports are handled automatically.

***

Server Not Appearing in Browser [#server-not-appearing-in-browser]

* Verify the query port (7778 UDP) is open
* Check that `Hidden` is set to `false` in `DedicatedServerConfig.json`
* Wait 1–2 minutes after startup for Steam to register the server
* Use direct connect as a workaround while waiting

***

"Failed to Connect to Steam" [#failed-to-connect-to-steam]

The server requires a working Steam connection on startup.

* Ensure SteamCMD libraries are present on the server
* Check that the network allows outbound connections to Steam's API servers
* Restart the server — this sometimes resolves transient Steam auth issues

***

Players Can't Connect from Same LAN [#players-cant-connect-from-same-lan]

This is a router limitation — not all routers support **NAT hairpin/reflection** (connecting to your own public IP from inside the network).

**Workarounds:**

* Connect using the local/internal IP instead of the public IP
* Enable hairpin NAT on your router if supported
* Use a VPN between LAN players

***

Mission Won't Load [#mission-wont-load]

* Check `DedicatedServerConfig.json` for JSON syntax errors — a missing comma or bracket breaks the whole file
* Verify mission names match exactly (case-sensitive): `Escalation`, `Terminal Control`, `Confrontation`, `Domination`, `Altercation`, `Breakout`
* For custom missions, the folder name must match the JSON filename inside it
* Check the server logs in `logs/` for specific error messages

***

Server Startup Verification [#server-startup-verification]

Check the console or log files for this message to confirm successful startup:

```
[DedicatedServerManager] Waiting for Players before loading next map
```

If you don't see this, look for error messages above it in the log.

***

Late-Game Performance Degradation [#late-game-performance-degradation]

Escalation mode in particular can slow down late-game as many units accumulate.

**Fixes:**

* Set `MaxTime` in the mission rotation to limit mission length (3600–7200 seconds recommended)
* Use `RotationType: 0` (sequential) to cycle through different missions
* Keep `MaxPlayers` at 16 or below for best performance
* Consider mixing in shorter missions like Confrontation or Altercation between Escalation rounds

***

High Player Disconnection Rates [#high-player-disconnection-rates]

* Check server logs for error-kick messages — the server auto-kicks players who cause errors by default
* Set `DisableErrorKick: true` in config if kicks are too aggressive
* Add trusted players to `ErrorKickImmuneListPaths` files

***

Config Changes Not Applying [#config-changes-not-applying]

* Always stop the server before editing `DedicatedServerConfig.json`
* Alternatively, use the `reload-config` remote command to reload without restarting (requires remote commands enabled)
* Verify JSON syntax — use a JSON validator if unsure

***

Client-Side Debugging [#client-side-debugging]

If a specific player has connection issues, their logs are at:

```
%USERPROFILE%\AppData\LocalLow\Shockfront\NuclearOption\Player.log
```

***

> 💡 **Still stuck?** Join our [Discord](https://discord.xgamingserver.com) for support.

Related Guides [#related-guides]

* [Configure Your Server](/docs/nuclear-option/configure-your-server)
* [Server Commands](/docs/nuclear-option/server-commands)
* [Game Modes & Missions](/docs/nuclear-option/game-modes)