Project Zomboid mods and Build 42: what to know

A Project Zomboid mod can download without a problem and still never load. Build 42 changed where a mod keeps its files, so a mod that was last updated before Build 42 came out, on 17 December 2024, downloads fine and is then not found by the game. The Outdated badge on the Workshop tab warns you about this.

What changed

A mod that has not been updated by its author for Build 42 has the old layout, so the game on Build 42 does not find it. We checked both ways on a Build 42.20 server: an old mod from 2018 downloaded and the game said it could not find it, while a current mod loaded.

The Outdated badge

On the Workshop tab a row marked Outdated says: "This mod was last updated in" and a date, "before the version of Project Zomboid your server runs. It will download, but the game will not load it. Look for an updated version on the Workshop, or one whose description says it supports the current build."

The check compares the mod's last update with the date of the Build 42 release. So:

• On Build 42, an Outdated mod will not load. Look for an updated mod.
• On Build 41 legacy, a mod made for Build 41 works, but it can still show Outdated, because the check looks at the date only. Trust the Did they load? report there.
• Popular does not mean current. Some of the most subscribed mods are old.

How to choose mods for your build

1. Open the mod's Workshop page and read its description and its recent updates for the build it supports.
2. Add it on the Workshop tab and look at the badge.
3. After a restart, check Did they load? (last start): How to check that your Project Zomboid mods loaded.

Players on the other build

Players must be on the same branch as the server. Build 41 and Build 42 mods are different, so a server on one build cannot use the mods of the other: How to choose Build 41 or Build 42 for your Project Zomboid server.

Mod ids with a backslash

Build 42 guides often write each Mod ID with a backslash in front, for example \UsefulBarrelsMP. The panel accepts that form in Enabled mods. We booted a Build 42.20 server with the plain name and it loaded the mod.

More: How to add mods to your Project Zomboid server, Your Project Zomboid mods do nothing.