Bug/Issue Multiplayer connection failed

Hello everyone
So I'm trying to play the multiplayer since the beta, but it never worked. It always said "connection failed". I thought I wait until the offical realise, maybe it will be fixed until then. So I tried it again yesterday with the new version 1.3.27, but it still didn't worked. My friend had as well the same version. I checked my firewall as well, but it already allows incoming connections. I don't know what to do anymore.

 

Very simple.
Step 1: Turn off your and your friend's firewall. If it's with invite codes, this will work.
Step 2: If its a local LAN party (2 cables from out of same router) Anyone can make this mistake, but the IP required is not that which is perceived by Google. The IP for local LAN will start with 99% of the time 192.168.2. This one is the one whoever joins needs to put in not the one on their own computer obviously.
Either way, you now have everything you need to figure out why its failing.