Can't play online with 3 players - Please read!

[tywald]

Do you wait when it freezes? Because it's intentional that it freezes for ~10s if it fails to connect, it will say "Communication error has occurred".

Usually when you get kicked out when quests starts it's almost always the firewall's fault or other programs that can block incoming and outgoing connections, for some disabling anti-virus helps like mcafee.

Fast memory should be turned off as well in the options.

All of you should do this btw, if you are the only person who do and they don't it will most likely still not work because fast memory kicks in for them and that fails when you try as 3 or 4(2 seems to work but the option explicitly states it's unstable so just go ahead and turn it off).

It's not really that many tricks to it, you don't need the 25% speed thing anymore since v0.9.8-890-g1445d5a and most people nowadays don't use older versions than that so that's one factor out of the way so it usually comes down to those two things(firewall and fast memory).