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This is advertised as a multiplayer game but the two servers (EU and US) both seem to have a problem where I can Create a game but when another player Joins (from the same LAN) they receive a "Connection Timeout" error.

This generates a "Player xyz left the game" message on the host's screen. So I don't think there are firewall issues.

From searching old forums, including here and Steam, the developer seems to have said this is a server issue. But does GOG validate that servers and subscriptions required for the multiplayer are kept up to date? Really I only want to play this over LAN and don't understand why that option wasn't made available.