ZombieBuddy

If you join without it, Viewpoint can look half-installed, Knox Inventory can sit there as a Lua mod with no grid, and the container fix never shows its jar. You will think the server is wrong. The server is waiting for the same jars everyone else already allowed.

Windows

Close Project Zomboid. Steam can stay open until the script says otherwise. In PowerShell, run the command on the join page. It writes pz-setup.ps1 into the current folder and runs it. The script subscribes to the Workshop list, copies the loader in, raises the game’s memory to 6 GB, and sets the Steam launch option to -agentlib:zbNative --.

Quit Steam when it asks, then start Steam again so the launch option is the one the game actually sees. When you start Project Zomboid and a jar prompt appears, click Allow. That includes Viewpoint, the Open All Containers fix, Knox Inventory, and Gael’s guns. Allow is not a one-time courtesy you can skip because the name looks unfamiliar.

When Knox says the Java part did not load

Quit the game. Check the Steam launch option. It should be -agentlib:zbNative -- with nothing else glued on, and in particular with no policy=deny-new. Start the game from Steam while holding Left Shift. When KnoxInventoryJava.jar is offered, click Allow. Quit once more, start normally, and only then join. Holding Shift is how you get the prompt back after a deny. Denying it and reconnecting will not wear the mod down.

The same pattern applies to any other jar you dismissed. A denied jar is a mod-shaped hole. Other players’ containers and your containers stop agreeing, which looks like theft and is usually a client.

Mac and Linux

Subscribe to ZombieBuddy, copy ZombieBuddy.jar into the game’s Java folder, and set the launch option to -javaagent:ZombieBuddy.jar --. The folders are in the loader’s install notes. The Windows-only installer is the official alternative to our script if you would rather not run a file from this site. Either path is fine. A mix of both, half-configured, is not.

VersionMismatch

If the disconnect says VersionMismatch, you are not being banned and the loader is not the cause. The server is matching the Project Zomboid build Steam expects, which for this community is 42.21 when the server is settled. Wait a few minutes and try Direct Connect again. Pinning an older beta in Steam properties will keep failing until you unpin it.

What the loader is not

It is not permission to add extra Java mods. The Workshop list on the join page is the list. errorMagnifier and Mod Update and Alert System are already on it so crashes and updates are visible. A personal “performance” mod that patches the same classes will get you a kick and a request to undo it.