Factorio Elevated Rails Mod Sync for Dedicated Server
With the launch of Factorio 2.0 and the Space Age expansion, the game's core features, Elevated Rails and Quality among them, are shipped as official mods. That produces a "Mod Mismatch" error on dedicated servers where players are prompted to download or sync mods even though they own the expansion. This guide covers how to fix those synchronisation loops.
Checked against the shipped builds on 20 September 2026: stable 2.0.77 and experimental 2.1.19. The mod list below is what those two distributions actually contain.
The Official Mod Set
A 2.0 install ships five mods in data/, and they are directories rather than files: core, base, elevated-rails, quality and space-age. On 2.1 there is a sixth, recycler, because the recycling recipes moved out of quality into a mod of their own. Vulcanus, Fulgora and Gleba are not mods: they are planets defined inside space-age, and there is nothing to enable for them separately.
The Sync Loop
Clients and server must run the same build. Because these features are mods, a mismatch surfaces as a mod problem rather than a version one, which is why the error names Elevated Rails when the real difference is the game version underneath it.
Correct Mod Installation for 2.0+
1. Use the mod-list.json Override
To ensure your Factorio dedicated server loads the expansion correctly, you must explicitly enable the mods in your mod-list.json. Simply placing the files in the mods/ folder is not enough.
{
"mods": [
{ "name": "base", "enabled": true },
{ "name": "elevated-rails", "enabled": true },
{ "name": "quality", "enabled": true },
{ "name": "space-age", "enabled": true }
]
}On a 2.1 server add the sixth one, or Space Age will not load its dependencies:
{ "name": "recycler", "enabled": true }2. Verify Auth Token for Downloads
If your server needs to fetch mods from the portal, it authenticates with the username and token fields in server-settings.json. That is the file to fill in on a headless server. The token comes from the Service Token section of your profile on factorio.com, and it is not your account password. See auth token setup.
The expansion itself is a different matter: Space Age, Elevated Rails and Quality ship inside the download, in data/, so a correctly installed server already has the files and only needs them enabled.
3. Client-Side "Synchronize Mods"
When joining, if the client says "Mods Mismatch", use the Synchronize and Restart button. The client matches the server's mod state and restarts to load it, which is why the restart is not optional.
Common Error: "Failed to load mod 'space-age': dependency 'base >= 2.0.0' not met." This means your Factorio Headless binary is outdated. Update to the latest stable build before enabling the expansion.
Space Age Server Ticks
Elevated Rails adds ramps and bridges, so a network built with them gives the train pathfinder more route options to weigh. Train pathfinding runs on the same single thread as the rest of the simulation, so headroom there comes from clock speed rather than cores. See hardware requirements.
Automate your expansion. Rent a Factorio Server with 1-click Space Age mod syncing and automated branch updates.