Mordhau Server Troubleshooting

Mordhau Server Troubleshooting

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Server Not Appearing in the Browser

Check 1 — All four ports are open

Mordhau needs UDP 7777, 27015, 15000, and 7778. The beacon port (15000) is particularly important for server discovery:

sudo ufw status

All four should show ALLOW. If any are missing:

sudo ufw allow 7777/udp
sudo ufw allow 27015/udp
sudo ufw allow 15000/udp
sudo ufw allow 7778/udp
sudo ufw reload

Check 2 — Cloud provider security group

VPS providers (AWS, DigitalOcean, Hetzner, Vultr) have a separate cloud firewall. Open all four UDP ports in your provider's control panel as well.

Check 3 — Give it time

Mordhau servers can take 5–10 minutes to appear in the browser after a restart, especially modded servers.

Check 4 — Direct connect test

Confirm the server is reachable by connecting directly in-game:

• Mordhau → Play → Server Browser → Direct Connect
• Enter YOUR_IP:7777

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Config Changes Not Saving / Reverting After Restart

Cause: You edited Game.ini while the server was running. Mordhau overwrites config files during a clean shutdown, discarding your edits.

Fix: Always follow this workflow:

sudo systemctl stop mordhau
# Edit Mordhau/Saved/Config/LinuxServer/Game.ini now
sudo systemctl start mordhau

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Server Crashes on Startup

Most common cause: Blank lines inside an INI section in Game.ini.

Bad (will crash):

[/Script/Mordhau.MordhauGameMode]
MapRotation=FFA_Cortile

MapRotation=TDM_Camp

Good (correct):

[/Script/Mordhau.MordhauGameMode]
MapRotation=FFA_Cortile
MapRotation=TDM_Camp

Check the server logs for the actual error:

tail -50 /home/steam/mordhau/Mordhau/Saved/Logs/Mordhau.log
# or via systemd:
journalctl -u mordhau -n 50

Other crash causes:

• Corrupt server files — run app_update 629800 validate via SteamCMD
• Incompatible mod — remove all Mods= entries and re-add one at a time to find the problem mod
• Missing 32-bit libs — install with sudo apt-get install lib32stdc++6 lib32gcc-s1

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Players Can't Connect

1. Confirm the server is running: ps aux | grep MordhauServer
2. Confirm UDP 7777 is reachable: nmap -sU -p 7777 YOUR_IP
3. Check no IP whitelist or password is accidentally set in Game.ini
4. Verify the server hasn't crashed — check journalctl -u mordhau -n 20

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Admins Not Working (PlayfabID Issue)

Mordhau uses PlayfabIDs — not SteamID64. If you put a SteamID in the Admins= field, the admin grant will silently fail.

How to get a PlayfabID:

1. Log in as admin in-game with adminlogin YourPassword
2. Run playerlist
3. Copy the PlayfabID from the output (it's a long alphanumeric string, not the Steam format STEAM_1:0:xxxxx)

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Map Not Found / changelevel Fails

Map names are case-sensitive and must include the correct game mode prefix:

• ✅ FL_Feitoria
• ❌ fl_feitoria
• ❌ Feitoria

Run adminlogin then check the map list in MapRotation in Game.ini to confirm spelling.

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High CPU / Performance Issues

• Reduce NetServerMaxTickRate in Engine.ini from 128 to 60 if the CPU is pegged
• Lower MaxSlots — 32–48 players is more manageable than 64 on standard hardware
• Check if a mod is causing excessive server load by removing mods one at a time