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

Abiotic Factor Can't Connect to a Server? Here's the Fix

When Abiotic Factor won't connect — the dedicated server is invisible in the list, friends time out, or you can't reach an online session — it's almost always the query port not being forwarded, a firewall block, or a wrong port number. Get the two UDP ports right and it works.

Exact details for Abiotic Factor

Ports to forward (UDP)
7777 (game) + 27015 (query)
Launch arguments
-PORT=7777 -QueryPort=27015 -ServerPassword=PASSWORD
RCON port
27020 (only if using remote admin)
Common cause of invisible server
Query port typo — 27105 instead of 27015 hides the server even on the LAN

Error codes

Dedicated server not visible in list The server runs but never appears to players

Cause: Query port 27015 not forwarded, or the wrong port entered.

Fix:
  1. Forward UDP 27015 (query) — the wrong number (e.g. 27105) makes the server invisible, even locally.
  2. Also forward UDP 7777 (game) to the host.
  3. Launch with -PORT=7777 -QueryPort=27015 so both are explicit.
  4. Add the server via IP:port as a fallback if it still won't list.
Friends time out on join The client can't reach the host session

Cause: Ports not open in router/firewall, or strict NAT.

Fix:
  1. Open UDP 7777 and 27015 on the router and Windows Firewall.
  2. Test the ports with CanYouSeeMe.org after forwarding.
  3. Set -MaxServerPlayers and a -ServerPassword so joins are predictable.
  4. Use a wired connection and restart the router to refresh NAT.
Online co-op session won't connect Non-dedicated co-op can't link players

Cause: Steam/EOS auth or version mismatch.

Fix:
  1. Both players update to the same Abiotic Factor build.
  2. Log out of Steam and back in, then relaunch.
  3. Verify game files on both machines.
  4. If it persists, switch to a dedicated server with forwarded ports.

Fixes that work for most Abiotic Factor errors

  1. Forward UDP 7777 (game) and 27015 (query).
  2. Launch with -PORT=7777 -QueryPort=27015.
  3. Double-check the query port is 27015, not 27105 — the typo hides the server.
  4. Allow the server through Windows Firewall (Private + Public).
  5. Test with CanYouSeeMe.org after forwarding.
  6. Match build versions for online co-op; verify files.

FAQ

What ports does an Abiotic Factor dedicated server need?

Two UDP ports: 7777 for the game and 27015 for the Steam query. Forward both on the router and set them with -PORT=7777 -QueryPort=27015 on the launch command.

Why is my Abiotic Factor server invisible even locally?

That's the classic port typo — forwarding 27105 instead of the correct query port 27015. Fix the query port to 27015 and the server appears again in the list.

RCON not connecting to my server?

RCON uses port 27020 by default. Forward it only if you actually use remote admin, and keep it separate from the 7777/27015 game and query ports.

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