Anno 1800 Lan Multiplayer Fixed -

Anno 1800 LAN Multiplayer Fix Guide

Prerequisites

  1. Ensure you and your friends have the same version of Anno 1800 (same patch level).
  2. Verify that your firewall and antivirus software are not blocking the game's network traffic.
  3. Make sure you have a stable network connection and can ping each other's IP addresses.

Step 1: Check Network Configuration

  1. Disable IPv6: Some users reported that disabling IPv6 helped resolve LAN multiplayer issues. Go to your network adapter properties and uncheck the box next to "Internet Protocol Version 6 (TCP/IPv6)".
  2. Set a static IP address: Assign a static IP address to each player's computer to avoid IP address conflicts. You can do this by going to your network adapter properties > Internet Protocol Version 4 (TCP/IPv4) > Properties > Use the following IP address.

Step 2: Configure Anno 1800 for LAN Multiplayer

  1. Launch Anno 1800 with the -lan argument: Add the -lan argument to the game's executable to enable LAN multiplayer. Right-click on the Anno 1800 shortcut > Properties > Target > add -lan at the end of the target field (e.g., "C:\Program Files (x86)\Ubisoft\Anno 1800\Anno1800.exe" -lan).
  2. Verify game settings: Ensure that the game is set to use the correct network settings. Go to Options > Network > and select "LAN" as the network type.

Step 3: Host and Join a LAN Multiplayer Game

  1. Host a game: One player creates a new game or loads an existing save > Options > Network > Host a game > select the desired game settings.
  2. Join a game: Other players join the game by selecting "Join Game" > enter the host player's IP address (or hostname) > select the game to join.

Common Issues and Solutions

Additional Troubleshooting Steps

Conclusion

does not have a dedicated "Offline LAN" button, you can play in a LAN-like environment by hosting a custom multiplayer session, though an active internet connection is typically required for the initial handshake via Ubisoft Connect.

Recent updates have addressed long-standing multiplayer stability issues that players often encountered in local or online play: Recent Multiplayer Fixes & Stability

Desync Hotfix (November 2025): A major update was released to resolve severe desync issues on PC. This fix stabilized sessions that previously crashed every few hours.

Mod Compatibility: Game Update 18 and subsequent patches fixed issues where differing mod setups caused matchmaking failures and immediate desyncs.

Save File Loading: A recurring bug where multiplayer saves failed to load has been mitigated. A common community fix involves having the host load the save solo first, creating a fresh save, and then re-inviting players to a new lobby. How to Set Up a "LAN" Session Game Updates | Anno 1800 Wiki | Fandom

Getting a smooth multiplayer session in Anno 1800 can feel harder than managing a five-island supply chain. Between desyncs, "LR40" errors, and NAT type issues, the 19th century isn't always stable.

If you are struggling to keep your friends in the game, follow this comprehensive guide to get your LAN and online multiplayer fixed for good. How to Fix Anno 1800 LAN and Multiplayer Issues 1. Solve the "LR40" Desync Error anno 1800 lan multiplayer fixed

The LR40 error is the most common plague in Anno 1800 multiplayer. It happens when one player's game state stops matching the others.

Check Game Versions: Ensure everyone has the same updates. Ubisoft Connect usually handles this, but a manual "Verify Files" is safer.

Synchronize Clocks: Believe it or not, if your Windows system time is out of sync by even a few seconds, the session can drop. Right-click your clock -> Adjust date/time -> Sync now.

Disable Background Downloads: Heavy bandwidth usage (like Steam updates or Windows Update) during a session is a primary trigger for desyncs. 2. Port Forwarding for Stable Connections

Anno 1800 uses specific ports to communicate. If your router’s firewall is too strict, you’ll never see your friends’ lobbies. Open these ports in your router settings: UDP: 18000, 18017, 3074, 3478, 4379, 4380, 27015, 27016

Once these are open, your NAT type should shift to "Open" or "Moderate," which is essential for hosting. 3. The "Virtual LAN" Workaround (Hamachi/Radmin)

If you are trying to play via LAN but the game doesn't "see" the host, the internal discovery mechanism is likely failing.

Use Radmin VPN: This is currently the most stable "Virtual LAN" software for Anno 1800.

Set Metric Levels: Windows often prioritizes your real Wi-Fi over the virtual LAN. Go to Network Connections.

Right-click your Virtual VPN adapter -> Properties -> IPv4 -> Advanced. Uncheck "Automatic Metric" and set it to 1.

Firewall Exceptions: Ensure both Anno1800.exe and your VPN software are allowed through the Windows Defender Firewall. 4. Hardware and Performance Fixes

Sometimes "lag" isn't network-related; it's a simulation bottleneck. If one player has a weak CPU, the whole multiplayer session will slow down to match their speed.

Match Graphics Settings: Have all players lower their settings to match the person with the weakest PC.

Clear Ubisoft Cache: Close the game, go to the Ubisoft Connect install folder, and delete the cache folder. This often clears "invisible" lobby bugs. Anno 1800 LAN Multiplayer Fix Guide Prerequisites

Cap Your FPS: Use Nvidia Control Panel or RivaTuner to cap everyone at 60 FPS. This reduces the strain on the simulation sync. 5. Ubisoft Connect Overlay Issues

The Ubisoft overlay is notorious for crashing multiplayer sessions or preventing invites from appearing.

Disable the Overlay: Open Ubisoft Connect settings and uncheck "Enable in-game overlay."

Use Direct Invites: Instead of looking for a lobby, have the host send a direct invite through the "Friends" list before the game starts. Quick Checklist for a Stable Game Verify game files on all PCs. Sync Windows time settings. Disable VPNs (unless using Radmin for LAN). Close Chrome or high-bandwidth apps. If you’re still seeing issues, let me know: Are you getting a specific error code (like LR40 or CF04)?

Are you playing on the same physical network or over the internet?

Do you have any mods installed (these must be identical for all players)?

For fans of the industrial revolution city-builder, "Anno 1800 LAN multiplayer fixed" has become a rallying cry for those trying to enjoy stable local or online sessions. While the game technically uses a lock-step mechanism to sync game states across all PCs—meaning only user inputs are shared to keep bandwidth low—this system often leads to frustrating "desync" events.

Whether you’re playing on a literal Local Area Network (LAN) or just trying to get a stable co-op session running through the internet, here is the comprehensive guide to fixing multiplayer issues in Anno 1800. 1. Fix Connection & Invitation Errors (LR05, LR39)

If you can’t even get your friends into the same lobby, the issue is usually related to how Ubisoft Connect communicates with your network or the game client.

Invite via Ubisoft Connect, not Steam: Many players find that the in-game "invite" button fails. Instead, minimize the game, open the Ubisoft Connect Desktop App, right-click your friend in the list, and select "Invite to Game" from there.

Disable IPv6: A common fix for "failed to connect to remote IP" (LR39) is to disable IPv6 on your network adapter. This forces the game to use the more stable IPv4 protocol.

Port Forwarding: Ensure your router allows traffic on UDP/TCP port 18000, which is the official port for Anno 1800's multiplayer services. 2. Solve "Desync Detected" (LR40) and "Trajan" Errors

Desyncs happen when one player’s game state stops matching the others. This often triggers an "LR40" error.

Verify Game Files: All players must have identical game data. Use the "Verify Files" tool in the Ubisoft Connect or Steam launcher to fix corrupted assets. Ensure you and your friends have the same

Clear the Sync Cache: Delete the Sync Data folder located in your Ubisoft Game Launcher directory (usually AppData/Local/Ubisoft Game Launcher/cache/http2/Default). All players should do this before restarting the game.

Match Version & Mods: Ensure everyone is on the same version (e.g., version 18.4). If using mods, every player must have the exact same mods installed and active. Even a single mismatched mod version will trigger a desync immediately. 3. Stability Fixes for Long Sessions

Long-running multiplayer games can suffer from "lag" when players switch sessions (e.g., moving from the Old World to the New World).

4) Version, DLC, and DLC compatibility

Preventative tips for smoother LAN sessions

Prerequisites:

When to contact support

If logs show authentication failures tied to Ubisoft services, or you’ve exhausted all steps above, gather:

If you’d like, I can produce:

Which of those would you like?

Finding a "fixed" LAN multiplayer experience in typically involves addressing the game's reliance on Ubisoft’s servers even for local play, as the game does not support a native, offline LAN mode. Stability is generally achieved by bypassing third-party launchers like Steam and ensuring all local network configurations are optimized. Core Connectivity Fixes

Most "LAN" issues are actually connectivity conflicts with Ubisoft Connect.

Bypass Steam Invites: Steam's invitation system is often cited as unreliable. Instead, add friends directly on Ubisoft Connect. Launch the game, minimize it, and use the Ubisoft Connect overlay or desktop app to right-click and "Invite to Game".

Enable UPnP: Many desyncs (like the LR40 error) are resolved by ensuring UPnP (Universal Plug and Play) is enabled in your router settings.

Firewall & Subnetting: Ensure both Anno 1800 and Ubisoft Connect are allowed through your Windows Firewall. For local play, verify both PCs are on the same subnet (e.g., both 192.168.1.x) and ideally using IPv4 rather than IPv6. Resolving Synchronization & Lag

Multiplayer in Anno 1800 uses a "lock-step" mechanism where every PC must simulate the exact same game state.

I searched for a report or guide titled "anno 1800 lan multiplayer fixed" , but as of now, there is no official or widely recognized document with that exact name from Ubisoft or major gaming outlets.

However, based on community discussions (Reddit, Steam, Ubisoft forums), here is a practical summary of what “fixing” LAN multiplayer in Anno 1800 actually means — and how players have made it work:

3) Router & NAT settings