Game is hanging after playing the "Outpost" twice. There are two ways to reproduce it. Either you play two "Outpost" cards in one round or you play one "Outpost" and then another "Outpost" in the following additional round (with three cards). The game is then stuck in a mode where you are requested to buy a card but can't buy one.
Example game is:
#158811434
In this game, we had to take several moves back in order to continue the game.
Thanks for the report, I'll forward it to the developer.