A friend of mine and I use hamachi to connect to each other via lan, and the past few days he has had endless issues with Hamachi, so we've together scoured the forums and tried anything that might be a fix to his issues. I'm asking for some sorta help here, I can get logs and put them here if you need them.
Go to preferences > settings > server connection > server address
Then change the port number (the default for me was 12975 so I changed it to 12976 instead)
This did the trick for me, hope it helps!