Sons of the Forest Server Troubleshooting

TL;DR – Most Sons of the Forest server tickets come down to the same four things: save corruption, port reachability, a mismatched dedicated-server version after a patch, or the server browser not advertising. Let's walk through them, plus the handful of weirder ones that surface every few weeks.

I've been on the support side of Sons of the Forest server hosting since Endnight first shipped the dedicated server tool, and the good news is that SotF has one of the cleaner failure modes in the survival-horror space. The bad news is that "cleaner" doesn't mean "rare" – patches land, saves rotate, routers block things, and a cannibal-infested island won't wait for you. Let's fix it.

1. The server won't start at all

Four culprits, in descending order of frequency.

Invalid dedicatedserver.cfg. SotF's config is JSON, and JSON doesn't forgive a trailing comma or an unquoted value. If you've been hand-editing the file in File Manager and the server refuses to launch after your last edit, that's almost always it. Open Configuration Files in the panel, look for a red parse error in the log on boot, and either fix the quote/brace you missed or paste the file into a JSON validator. A clean config is a server that starts.

Port already in use. The server runs a self-test on launch – if it can't bind its game/query/auth UDP ports, it refuses to boot and prints UDP <portname> <number> is closed or port in use. On LOW.MS this is auto-allocated so it's rare, but it happens after a failed shutdown left a ghost process holding the port. Restart the server from the panel and the wrapper will clean it up.

Dedicated-server tool out of date. Every so often Endnight ships a server-only patch (the v0.59 dedicated-server update was the textbook example). Run Steam Update from the sidebar and it'll pull the latest build of Steam app 2465200.

Corrupt save. If the server boots fine with a fresh save but crashes mid-boot on your real one, you've hit a save-side corruption. Skip to section 4 – that's a Cloud Restore job.

2. Server starts but doesn't appear in the browser

This is the ticket I see most on a Friday night. The server process is running (you can see it in Current Activity & Stats), logs look clean, but your friends can't find it in the Dedicated tab.

Symptom / Cause / Fix, inline:

• Server shows up in LAN, not Internet – LanOnly is set to true in dedicatedserver.cfg. Flip it to false, save, restart.
• Server doesn't show up anywhere – the server is advertising, but Steam's master server either doesn't know about it or isn't surfacing it to your client. Ten times out of ten on shared hosting this resolves with a direct connect: press ` in the main menu lobby and paste IP:port from the panel. The server browser is flaky; direct connect isn't.
• Only the host machine can see it on the same LAN – classic NAT-loopback/hairpin issue on the host's router. Irrelevant to LOW.MS customers (different networks), useful to know when you're helping a friend running at home.
• Appears briefly, then disappears – Steam has de-listed you for a failed query. Check your query port isn't being stripped by a firewall between the panel and Steam; our wrapper handles this automatically but rare ISP-level routes still interfere.

If the panel's Log Viewer shows Server registered with Steam and your friends still can't see it, go straight to direct connect. Don't burn an hour on the browser.

3. Players can't connect

Three things, and you can triage them in about sixty seconds.

1. Version mismatch. Endnight patched the client overnight and the server is still on yesterday's build, or vice-versa. The client will tell the player "incompatible version" – not always cleanly, sometimes just a silent disconnect at the loading screen. Open Steam Update in the sidebar and let it run; if the server was already up to date, ask the player to verify their client via Steam.
2. Server full. SotF caps at 8 players. If your 8-slot plan has 8 people in it, nobody else gets in – that's not a bug, that's the engine.
3. Password typo. If you've set a password in config, it's case-sensitive and every character counts. Paste it in a shared doc for the group rather than typing it from memory.

A fourth edge case: a player's Steam has gone offline or their own network is routing oddly. If everyone else connects fine and it's just one person, the issue is their end – ask them to restart Steam or try a direct connect.

4. Save corruption and "we lost our progress"

Endnight's save system rotates save slots and writes autosaves, which is usually a lifesaver and occasionally the problem. The most common form of this ticket is: "we played for three hours, the server crashed, and when we came back we were on last night's save."

The fix is always the same on our platform – Cloud Backup and Cloud Restore from the sidebar. We snapshot the save data on a schedule plus at every graceful shutdown, so there is almost always a recoverable version sitting one click away. Stop the server, open Cloud Restore, pick a snapshot from before the crash, confirm, start the server.

If the ticket is "we want to bring our singleplayer save up here," that's a different workflow – see uploading your Sons of the Forest save to your server for the step-by-step. Local saves live under %LOCALAPPDATA%\SonsOfTheForest\Saves\<SteamID>\Multiplayer\<saveID> and copy up cleanly if you grab the whole folder.

One wart worth flagging: when uploading a save, some players have reported one member of the group losing their inventory while the rest keep theirs. It's an Endnight-side quirk tied to per-player state in the save – usually fixable by restoring an older backup or, if nothing else works, accepting the lost items and using cheatstick (admin only) to re-grant them.

5. Performance – lag, desync, rubber-banding

SotF isn't a tick-rate-tunable game the way Rust or Valheim are. What you can do is:

Rule out hardware. We ship 10 GB RAM on the default plan, and that's fine for 6–8 players and a sensible base. If your tribe has built a 500+ structure fort with dozens of traps, effigies, and solar panels, the server will start paging and everything will feel sluggish. Bump to the 15, 20, 25 or 30 GB RAM tier through Configurable Resources on the plan page. If the CPU is the pinch point – you'll see it on Current Activity & Stats – add the Latest CPU option (guaranteed Ryzen 7950X/9950X) for a cleaner single-thread ceiling.

Rule out client-side. Ask one player to check their ping to the server IP. If they're at 180 ms and everyone else is at 30, that's their network, not yours. Region selection matters for SotF because the engine is fairly sensitive to latency spikes.

Rule out mid-session drift. The dedicated server will degrade over a long uptime, especially with a large base. Schedule a nightly restart via the panel – I've fixed more "feels sluggish by Sunday" tickets with one restart than with any config change.

6. Mods not working (the honest answer)

SotF has no official mod support. No Steam Workshop, no supported API, no -mods flag. Community tools like RedLoader exist for singleplayer client-side tweaks, but they're not something a dedicated server can authoritatively enforce, and running anything that touches game code in multiplayer tends to desync or outright crash sessions.

If a customer tickets in with "my mod isn't working," the honest answer is that we don't support modded SotF servers – not because we don't want to, but because Endnight hasn't shipped the hooks that would make it reliable. Play vanilla, use cheatstick for admin-side flexibility, and wait for Endnight. I'll update this article the day it changes.

7. After a Steam update, the server crashes

Endnight patches occasionally break save compatibility. It's not malicious – it's the cost of a living game – but it bites. If your server updated cleanly and now crashes on world load immediately after a patch, and your save is from before the patch, you've hit the compat window.

The pragmatic fix is a Cloud Restore to a snapshot from after the update but before the crash, if one exists – sometimes the game will migrate the save on first boot and you just need to let it finish. If there's no clean save, a fresh world is sometimes the path of least resistance. Keep the old save zipped up in File Manager in case Endnight patches in a fixup later.

8. Admin commands don't work

Three checks, in order:

• Is your SteamID64 (the 17-digit one, not your vanity URL) on its own line in ownerswhitelist.txt in the save directory? Any other format – Steam ID3, friend code, vanity name – won't work.
• Did you restart the server after editing the file? Hot-reload doesn't happen.
• Are you typing cheatstick in chat (press Enter, type, Enter) and then pressing F1? The panel won't open if you haven't flipped the cheatstick flag first, and your keyboard has to be on a US-ish layout for the keystroke to register properly.

If all three are right and it's still silent, double-check you're editing the whitelist in the active save's folder – SotF has per-save whitelists and it's easy to edit the wrong one after restoring a backup.

The panel tools worth knowing

When a ticket lands, these are the sidebar items I reach for, in order: Log Viewer for the "what actually happened" answer, Web Console if I need to issue a command live, Current Activity & Stats to check CPU/RAM/player count, Configuration Files to fix a bad edit, Cloud Backup and Cloud Restore for save problems, Steam Update after a patch, Backup Manager for manual snapshots, File Manager for direct save upload or whitelist edits, and Commandline Manager when I need to change a startup argument. If you've touched each of those once, you can solve 95% of the tickets that come through.

For the setup and config side of things you probably want Sons of the Forest server configuration or the join-your-server walkthrough. The wider community knowledge base lives at sonsoftheforest.wiki.gg and the Steam Community discussions for app 1326470 are usually on top of any new-patch quirks before I am.

Still stuck after all that? Open a ticket with the server ID and a timestamp of when the problem started – that's all I need to pull logs and take it from there.