Fix common Factorio server errors

Most Factorio server problems come down to a wrong address or port, a version or mod mismatch, or a missing token. Find the message you see below. The messages are written the way the game shows them, and the most common ones are first.

Before anything else, open Overview and check the server says Running or Sleeping. If it says Stopped, press Start. If it crashed, the Console shows a crash helper card with a hint and a fix button when it recognises the problem.

Joining the server

“Could not establish network communication with server.”

The game couldn’t reach your server.

1. Check the address and port. Copy them from the address card on Overview, like megabase.play.wilderack.com:30197. Use that port, not 34197.
2. Make sure you typed both in the IP address and port box, with the colon between them.
3. If the server was asleep, it may have needed a moment to wake. Wait a few seconds and connect again.
4. Still failing? Open the wake link play.wilderack.com/w/megabase, wake the server, then connect.
5. Restart the server from Overview and try once more.

“Version mismatch detected!”

Your game and the server run different versions. The game says whether the server is running a newer or older version.

• The server is newer: update your game. On Steam, restart Steam so it fetches the update. Make sure you’re not on an old beta branch under Properties > Betas.
• The server is older: check the game version in Settings. If it’s pinned, unpin it or pick your version. A restart then moves the server to it.
• Nintendo Switch players: the Switch often runs a version behind PC. Pin the server to the Switch’s version in Settings while they play.

“Mods mismatch detected!”

Your mods don’t match the server’s. The game lists each difference, such as a mod that is only on the server, one that is not on the server, or a different version.

1. In the same dialog, select Sync mods with server.
2. Make sure Sync startup settings is ticked.
3. Let the game download the mods and restart. It then joins.

If the dialog says some mods aren’t available on the mod portal, sync can’t fetch them. Install those by hand, using the same files the server uses. If you have extra mods the server doesn’t, sync turns them off so your mods match. You can turn them back on later in the game’s Mods menu.

The password doesn’t work

The game asks for a password when you connect, and won’t let you in.

1. Check the password in Settings in the panel. Passwords care about capital letters.
2. Type it in the Password box under Connect to address, not in the address box.
3. If you changed it in the game with /config set password, set the same password in Settings as well, so the server keeps it after a restart.

“Your username is not whitelisted on this server.”

The whitelist is on, and your factorio.com username isn’t on it. An admin adds you with /whitelist add yourname in game, or in the allow list in Settings. To turn the whitelist off, an admin types /whitelist disable.

“The player limit was reached in this game.”

The server is full. Raise max_players in Settings or server-settings.json, or set it to 0 for no limit. Admins can always join a full server. To let regulars in when it’s full, turn on ignore_player_limit_for_returning_players.

“Your username is banned in this game.”

An admin banned this username. If it was a mistake, an admin can type /unban name in game, or remove the name from the ban list in Settings.

“User with your name is already in the game.”

The server still thinks your last session is connected, often after a crash or a dropped connection. Wait a minute and connect again. An admin can also /kick the old session.

A friend without Space Age can’t join

A Space Age server needs every player to own Space Age, and the game won’t let them join without it. Either they get the expansion, or you play a vanilla map. Switch the server type in Settings, which makes a backup first. A Space Age save won’t load on a vanilla server, so that means a new or older vanilla map.

While you play

“Server is not responding”

The game stopped hearing from the server for a moment.

1. Wait 10 to 20 seconds. On a big map, a long autosave can cause this.
2. If it happens at every autosave, raise autosave_interval. See Factorio performance tips.
3. If it doesn’t come back, check Overview. If the server crashed, the Console crash helper shows why.
4. Check your own connection. Wi-Fi far from the router can drop out.

“You desynchronized from the game.”

A desync means your game stopped matching the server’s. The game drops you and builds a desync report, then lets you reconnect. Lag and slow internet don’t cause desyncs. Bugs do, most often in mods.

1. Reconnect. One-off desyncs often don’t come back.
2. If they keep happening, think about which mod you added or updated last. Remove it from Mods and test.
3. If you play without mods, Wube asks for a bug report on the official forum, with the desync report and what players were doing.

“You have been disconnected as your computer or network wasn’t fast enough to keep up with the server.”

Your PC or connection couldn’t keep up with a big factory. Close other heavy programs, use a wired connection if you can, and check that the server’s UPS is healthy. See Factorio performance tips.

Running the server

The server doesn’t show in Browse public games

All of these must be true:

1. visibility > public is true in server-settings.json, or listing is turned on in Settings.
2. Your factorio.com username and token are on the server. See Add your factorio.com token.
3. The server is awake. A sleeping server drops off the list, so set Settings > Sleep to always-on.

If the Console shows errors about the matching server (Factorio’s public list), the token is usually wrong or was reset. Add the new one in Settings and restart.

“Map version … cannot be loaded because it is higher than the game version”

The save was made in a newer Factorio than the server runs. This happens when you upload a save from a newer or experimental version.

1. Check the game version in Settings. If it’s pinned, unpin it or pick a version at least as new as the save.
2. Restart the server.
3. If you play on Steam’s experimental branch, the server needs that version too, or play the save on the normal branch.

The Mods tab can’t download mods

The mod portal needs your factorio.com username and token. Add or update them in Settings. If you reset your token on factorio.com, the old one stops working, so paste the new one. See Add your factorio.com token.

The server won’t start after a mod change

1. Open the Console and look for the crash helper card. It often names the mod.
2. Remove the mod you added or updated last from Mods, then start again.
3. If a mod says it requires Space Age, either remove it or switch the server type to Space Age in Settings.
4. If nothing works, restore the backup we made before the change, from Backups.

Still stuck?

Write to support@wilderack.com with your server’s address and what you see. A real person reads every message. Our status page shows if anything is wrong on our side.