Build 41 initially had multiplayer disabled for testing but it was reintroduced in 41.60 and stabilized through updates like 41.73.
Build 41 was a massive overhaul of the game, often considered the "new foundation" for its future. The 41.73 update specifically included: Project.Zomboid.v41.73-OFME.rar
Introduction of the foraging and search system, a new in-game map, and an overhauled sound system. Build 41 initially had multiplayer disabled for testing