Yesterday, I was having a problem where I couldn't connect to my friend's minecraft Lan (I would technically connect, but I would just be floating in a blue void. After a few seconds, my friends would tell me that the game said I disconnected)
I tried almost every fix I could find, and I eventually got it working by creating a rules for hamachi-2-ui.exe in my Firewall, which changed my friend (the one hosting the lan, not everyone else) from relayed tunnel to direct tunnel, and I was able to connect. Today, that seems to no longer be working and I have no idea why.
Some support on this would be appreciated, because I am very, very tired and frustrated with it at this point.