🎮 Game Error Codes What it means & how to fix it

Space Engineers Won't Let You Join a Server? Here's the Fix

Most 'Space Engineers can't join server' issues are a mods mismatch, a version difference, or the server browser dropping entries. The fastest fix in 2026: subscribe to the server's full mod list, verify game files, and join by direct IP — for self-hosted servers, forward UDP 27016.

Space Engineers dedicated server — exact port, config & save path

Steam port (UDP)
27016
Server config file
%APPDATA%\SpaceEngineersDedicated\SpaceEngineers-Dedicated.cfg
Save path
%APPDATA%\SpaceEngineersDedicated\Saves
Common cause of 'cannot join'
27016 UDP not forwarded — the server never appears in the friends/LAN browser

Last verified: September 2026

Error codes

Connection failed / can't reach server The client can't establish a session

Cause: Version mismatch, missing mods, or UDP port not reachable.

Fix:
  1. Subscribe to every mod in the server's list before joining.
  2. Verify game files so your build matches the server's.
  3. Join by direct IP (server list > right-click > Connect, or add to Favorites in Steam).
  4. Self-host: forward UDP 27016 (or your configured port) to the server machine.
Server not in the browser The server is up but doesn't appear

Cause: The public list is unreliable or the server is set to Friends/Private.

Fix:
  1. Add the server to Steam Favorites by IP:Port and connect from there.
  2. Host: set visibility to Public and confirm the port is open.
  3. Give the server a minute to register after boot.

Fixes that work for most Space Engineers errors

  1. Subscribe to the server's exact mod list before joining.
  2. Verify game files after each update to match the server build.
  3. Connect by direct IP / Steam Favorites, not the in-game browser.
  4. Self-hosted: forward UDP 27016 and allow SpaceEngineersDedicated through the firewall.
  5. Set server visibility to Public if you want it listed.
  6. Restart Steam and retry if the list is empty.

FAQ

Why can't I join a Space Engineers server?

Usually a mod or version mismatch, or the browser dropped the entry. Subscribe to the server's full mod list, verify game files, and connect by direct IP through Steam Favorites.

What port does a Space Engineers dedicated server use?

UDP 27016 by default (configurable). Forward that port to the server machine and allow the dedicated-server executable through the firewall so clients can reach it.

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