While Build 40 is a complete experience, the newer Build 41 is effectively a "different game" according to community consensus. Build 41 introduced 3D character models, a complete animation overhaul, and significantly more difficult combat. Players typically stick to Build 40 if their PC struggles with the 3D requirements of Build 41 or if they are finishing long-running multiplayer saves on older servers. Status and Build History - Project Zomboid
To recap the easiest method:
Do not use mods designed for Build 41. They will crash instantly.
Project Zomboid Build 40 Download — High Quality New
While Build 40 is a complete experience, the newer Build 41 is effectively a "different game" according to community consensus. Build 41 introduced 3D character models, a complete animation overhaul, and significantly more difficult combat. Players typically stick to Build 40 if their PC struggles with the 3D requirements of Build 41 or if they are finishing long-running multiplayer saves on older servers. Status and Build History - Project Zomboid
To recap the easiest method:
Do not use mods designed for Build 41. They will crash instantly.