Friend can't connect to LAN server.
There latest.log: https://gist.github.com/Ibirtem/7353bc789cff95fed3bc4aa19e57880e
Happens with Antique Atlas mod

Frustrating. I’ve seen this before, but it doesn’t usually cause issues beyond JEI not working. I’m not even sure if it’s my fault or JEI’s, but as far as I can tell, the fix requires a complete rewrite of Eidolon’s recipes to use the new JSON system.

I will be doing this, but it will take a while and probably not be out for some time.

It's strange that I don't crash and everything works well when entering in singleplayer, It's just friend can't join to LAN. Logs files can be wrong. Maybe try to create a report for AntiqueAtlas? Maybe they will fix the error without big changes and works

Antique Atlas is irrelevant here. It’s an issue with JEI and Eidolon, and it’s easier to fix on Eidolon’s side.