Choosing a player to trade with
Maybe I'm an idiot, but I can't figure out how to choose a player to trade with. I have only been playing single player. All I can do is click the green check which allows me to trade with the middle player.
Sounds like only the middle player wanted to trade. If multiple players want to trade you will see multiple checks (x means doesn't want to trade, check means player will trade)
p.s. For open trade you can leave one side blank and see what others are willing to trade.