Ensure the steam_appid.txt contains the correct ID for AOE III DE (933110). Open your Windows Firewall settings.
This allows users to play multiplayer matches over a local network without an internet connection, effectively "fixing" the limitation imposed by the official client. age of empires iii de lan fix mrgoldberg extra quality
Check both and Public boxes for the game and the emulator processes. Network Profile Configuration Ensure the steam_appid