https://forums.galciv3.com/471767/page/1/
"We've fixed made some improvements to multiplayer especially in reducing the number of disconnects. We have also increased the maximum multiplayer map size to "gigantic."
To enable the opt-in, please do the following:
1. Select "Galactic Civiliation III" in your Steam Library list
2. Right-click and select Properties
3. Select the BETAS tab
From the dropdown, select opt-in v1.3.2 and click Close (if you don't see this option, restart Steam)
Changes
+ Increased maximum multiplayer map size to Gigantic
+ Fixed a problem where peers were not updating their heartbeat while loading the map and thus causing a disconnect.
+ Fixed a problem where all of the players would choose "ready" but the host could not start the game.
+ Separated the networking and loading processing to different threads to prevent timeouts while starting the game.
+ Prevented a multiplayer disconnect issue caused by the player spending the Thalan's bonus tech points in the first turn.
+ Fixed a few stuck turn problems"
