Players using Wine/Proton on Linux or Steam Deck have reported additional hurdles with Anno 1800 multiplayer:
Corrupted temporary files in your Ubisoft launcher can cause matchmaking and invite systems to break entirely.
Turn your router off for 30 seconds and back on to refresh the connection. 4. Solving Late-Game Desync (LR40 Errors)
Ubisoft has actively patched several LAN-related connectivity problems:
Once everyone appears in the virtual lobby, launch Anno 1800. anno 1800 lan multiplayer fixed
Disable any virtual adapters (e.g., Hamachi, RADMIN, VirtualBox, or active VPNs) if you are playing on a physical local network.
Complete Troubleshooting Guide: How to Get Anno 1800 LAN and Multiplayer Fixed
Corrupted simulation data can permanently block players from joining a hosted lobby, even if your network is perfect. Clearing this temporary cache allows a fresh simulation state to download from the host. Close Anno 1800 entirely.
Press the Windows Key, type , and hit Enter. Locate the Synchronize your clock section in the menu. Players using Wine/Proton on Linux or Steam Deck
Most issues are caused by mismatched mods or Ubisoft Connect being in "Offline Mode." To fix: Make sure everyone is Online in Ubisoft Connect Disable all mods to test connection. Verify files on Steam/Ubisoft.
Anno 1800 LAN Multiplayer Fixed: Ultimate Connectivity Guide
Click your network icon (Wi-Fi or Ethernet) in the Windows system tray. Select under your active connection. Change the Network Profile type from Public to Private .
Many desyncs (like the LR40 error) are resolved by ensuring UPnP (Universal Plug and Play) is enabled in your router settings. Solving Late-Game Desync (LR40 Errors) Ubisoft has actively
or specific desyncs, I can help you dig deeper. To narrow it down, let me know: Are you getting a specific error code (like LR40)? Are you using Mod Manager Does the crash happen at 30 minutes
Check game version & updates, match network settings (firewalls, ports, UPnP), verify files, ensure consistent game/crew/season pass DLC across players, and use an offline LAN workaround (direct IP/host tool) if the in-game LAN matchmaking fails.
| Error Code | Meaning | The LAN Fix | | :--- | :--- | :--- | | | Relay server timeout | Switch to Direct Connection . The host is trying to use Ubisoft servers. | | Desync (CTD) | Packet loss | Check your Ethernet cables. Disable WiFi on both PCs if hardwired. | | "Unable to join" | Port 18000 blocked | Manually forward ports OR disable Windows Defender entirely for 5 mins to test. | | Endless Loading | IPv6 conflict | Disable IPv6 on your Network Adapter properties. Force IPv4. |
The notorious LR40 error indicates that the simulation state on one computer no longer matches the host computer. If the error occurs repeatedly after applying network fixes, the issue lies in corrupted cache files. Close Anno 1800 completely on all systems.