My friend (call him friend1) and I can play my Hamachi server together no bother. When I asked my friend (call him friend2) if he wanted to join, he said yes. My friend (friend1) can play but the other one can't. We have tried everything, including port forwarding. This is really annoying and I don't want to 60 euro for a static IP!
So basically a lot of people have this problem, like lot's. So this is what i'd do. maybe you'v done this but, might help!
First: Make sure all three of you have hamachi open. Then YOU have to make a new network on the same hamachi.
Second: After that give the details of the hamachi's address and password to all three of you.
Third: Check that the list of people on the hamachi. Should be only two people. Since as you can't see yourself.
Fourth: Start playing on the world, And open to lan. Then it should pop up on their server list. If not then get them to right click your account on hamachi and then they should click "get IPv4 address" (warning it might not say that i havn't used it in a while.) Make sure they don't click the IPv6. cause that isn't what they need. Other ways of doing this is by going into the cmd and doing "ip config" and looking for your ip. but that's harder...
That should work. Some things to do is check if your firewall is up. both be on the same version.
If that dosn't work then i can't think of much more to do other then:
Let friend1(or friend2) host.
restart your laptop. (Sometimes my internet stops working right and then i restart and it's all good.)
And if there is mods and the other player dosn't have it they can't connect.
Hmm... Just realized how big this post is. Awesome. Anyway hope this helps. Good luck!
Check your firewall settings. If that does not work check to make sure that you do not have nine other people on your Hamachi network. Hamachi is limited to 10 people on the network.
Check to make sure that you are on the same subnet as your friend.
Also check to make sure that the games are the same version.
Try posting some debug logs.
Hope this helped!