: Ensure all players are on the exact same game version. In Ubisoft Connect , select Anno 1800 and choose "Verify files" to fix corrupted data that might cause mismatches. Client & Software Fixes

If your friends get stuck loading at 60% or get "Failed to Join Game" errors:

If playing over a virtual LAN (like Hamachi or Radmin), ensure all players are on the same virtual subnet. Option 2: The "LAN via Virtual Network" Guide

is allowed through the Windows Firewall for both Public and Private networks. Troubleshooting Desyncs & Mods