Lan worlds cannot be joined

I was going to play with a friend offline with LAN, so I opened to LAN
What I expected to happen was...:
I thought that he'd be able to join
What actually happened was...:
He was not able to join and received a message something like this: Could not connect: Connection refused
Steps to Reproduce:
1. Two people log in to minecraft with the minecraft client, without being able to connect to mojang, play offline.
2. One start/load a world
3. Open to LAN
4. The other person try to join the LAN