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Connection Issues (1.0)

Satisfactory Guide • Updated May 21, 2026

Satisfactory 1.0+: Connection & Auth Fixes

Since the 1.0 Release, dedicated servers have changed significantly. The old ports (15777/15000) are gone, and a new secure authentication system is in place. This guide fixes the most common errors.

Patch 1.1+ Update: As of Patch 1.1.0.0, Satisfactory servers now require two ports: Port 7777 (UDP+TCP) and Port 8888 (TCP) for reliable messaging. If you upgraded from 1.0, you must open port 8888!

1. Required Ports (1.1+)

Port 7777 (UDP+TCP) - Game traffic
Port 8888 (TCP) - Reliable messaging
Old ports 15777/15000 are obsolete.

2. "Encryption Token Missing"

This error happens when you try to join via Steam/Epic friends list. You cannot do this. You must use the in-game Server Manager.

3. Tier 0 Skipped?

Not a bug. Dedicated Servers skip the "Onboarding" tutorial phase. You start at Tier 2 functionality by design.

Port Configuration (Critical)

Port Protocol Purpose Required Since
7777 UDP + TCP Game traffic, Server Manager 1.0
8888 TCP only Reliable messaging 1.1.0.0

Firewall Rules

# PowerShell (Run as Administrator)
New-NetFirewallRule -DisplayName "Satisfactory 7777 UDP" -Direction Inbound -Protocol UDP -LocalPort 7777 -Action Allow
New-NetFirewallRule -DisplayName "Satisfactory 7777 TCP" -Direction Inbound -Protocol TCP -LocalPort 7777 -Action Allow
New-NetFirewallRule -DisplayName "Satisfactory 8888 TCP" -Direction Inbound -Protocol TCP -LocalPort 8888 -Action Allow

Multiple Servers: If running multiple instances, use -ReliablePort=NNNN launch parameter to set different reliable ports for each server.

Authentication Issues

"Invalid Authentication Token"

  • Token Expired: Authentication tokens have limited lifetime. Generate new token.
  • Password Change: If admin changed server password, old tokens become invalid.
  • Corrupted Token: Token file corrupted. Remove server and re-add.
  • Network Issues: Connection interrupted during authentication. Try again.

"API Disconnected"

  • Server Offline: Server not responding to authentication requests.
  • API Timeout: Server taking too long to respond. Retry connection.
  • Port Blocked: Port 7777 blocked by firewall or ISP.
  • Service Down: Satisfactory authentication service experiencing issues.

"Failed to Connect"

  • Version Mismatch: Client and server on different game versions.
  • Mod Incompatibility: Mods causing connection issues. Try vanilla.
  • Network Unstable: Connection dropping during handshake. Check internet.
  • Server Full: Maximum player capacity reached. Wait for slot.

Advanced: Docker, Multihome & VM Issues

The Multihome Bug

Do NOT use the -multihome=X.X.X.X flag. It breaks the internal API binding on 1.0+ servers, causing "Failed to connect to Server API" errors. There is no workaround except removing this flag.

Docker Configuration

  • Network Mode: Use network_mode: host instead of bridge mode
  • Port Mapping: If using bridge mode, map both 7777:7777/udp, 7777:7777/tcp, AND 8888:8888/tcp
  • Linux TCP Binding: If TCP:7777 binds to 127.0.0.1, use rinetd to create an internal port-forward

VM/Proxmox Issues

  • CPU Type: Do NOT use KVM64 CPU type in Proxmox - it causes immediate crashes on load
  • Recommended: Use host CPU type or another modern processor emulation
  • Memory: Allocate at least 8GB RAM to the VM

Server Shows "Offline"? If your server says "Offline" but is clearly running, restart it. The 1.0+ server has a known bug where the API "goes to sleep" after long periods of inactivity.

"It was working, now it isn't" — the ISP IP change scenario (refreshed 2026-05)

A common report after a power outage, modem reboot, or several days away from the game: the dedicated server still runs but clients can no longer join, even though nothing was changed. The cause is usually one of two things: (a) your ISP assigned a new public IP to your modem during the outage, and your port forwarding now points to a private IP that no longer matches your host machine, or (b) the modem's UPnP table was cleared on reboot and the port forwarding rule needs to be re-applied.

Diagnostic order:

  1. From the host machine, check the current LAN IP: ipconfig on Windows or ip addr on Linux. Compare to the LAN IP your router is forwarding port 7777 to. If they differ, update the rule.
  2. Check your public IP from a phone on cellular: https://whatismyip.com. If this differs from the IP your friends remember, you have a dynamic IP and need to either set up dynamic DNS or share the new IP each time.
  3. Verify port 7777 and 8888 are still open externally: https://www.yougetsignal.com/tools/open-ports/ with your new public IP.
  4. If steps 1-3 are clean but joining still fails with "Encryption Token Missing," remove the server from your in-game Server Manager and re-add it using the current IP. The stored token references the old endpoint and won't update.

Tuning Engine.ini MaxInternetClientRate

If connections work but feel laggy under load (vehicles jittery, projectile delays, late actor replication), the default MaxInternetClientRate value of 10 KB/s is the bottleneck. The community-tested value for stable Satisfactory hosting is much higher:

# In FactoryGame/Saved/Config/<WindowsServer|LinuxServer>/Engine.ini
[/Script/Engine.NetworkSettings]
MaxInternetClientRate=104857600
MaxClientRate=104857600
RelevantTimeout=5.0
SpawnPrioritySeconds=2.0

The 104857600 figure is 100 MB/s, deliberately higher than any realistic single-client need. This eliminates the rate-clamp stalls that happen during burst replication windows (large groups of buildings updating simultaneously, vehicle physics ticks, train arrivals). See our network quality CPU bottleneck guide for the relationship between this setting and CPU load.

After editing Engine.ini, restart the dedicated server completely. Edits applied while the server is running may be overwritten on shutdown by the server's autosave of its config state.

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