The Indie Stone has issued an October 21, 2026, Project Zomboid modding notice with a blunt message: Java-based mods are not officially supported, can create security vulnerabilities, and will be fundamentally broken by future updates without warning. Only Lua-based modding is officially supported.

Java is Project Zomboid’s core coding language. With Java-based loaders and frameworks, modders can change the game’s code directly, enabling radical overhauls. That same access means Java mods can potentially create security vulnerabilities. Unlike regular Lua mods, they sit outside the “confines” of Project Zomboid’s code; The Indie Stone’s comparison is that a Lua mod might repaint a house, while a Java mod can build a new house nearby—possibly without your knowledge and with an unseen back door. Installing one means letting third-party code run on your machine. The studio stresses that not all Java mods are malicious or automatically risky, but they require a different level of trust.

In the vast majority of cases, Java mods require manual installation, downloads from external websites, a special loader, or steps beyond clicking “Subscribe” on the Steam Workshop. The Indie Stone says players should download mods only from trusted sources and authors, regardless of language. It strongly encourages Java modders to provide open-source or reproducible builds, and recommends players look for those qualities; transparency can offer peace of mind, but neither guarantees safety. Steam Workshop’s flag and report systems and the popularity of many mods are reassuring, not a safety guarantee. For other sources, check whether source code is public and distributed files can be independently verified; if not, be very careful.

Java-based mods—including third-party loaders, frameworks, and changes to the game’s underlying implementation—are not officially supported, even though Project Zomboid is written in Java. Its internal implementation is not a supported modding interface. Any mod in any language can break alongside an update, but Java mods rely on internal code that will always change; The Indie Stone says new updates will break them without warning. It cannot provide technical support for Java mods, resolve compatibility problems with other mods, or dedicate development resources to them.

Bug reports are investigated only when the bug is found in an unmodded game save. Players encountering problems with any mod, Java or Lua, must reproduce the issue without mods before submitting; reports must be reproducible without mods to be considered, and that does not guarantee an investigation or fix. The studio says the policy is not a judgment on mods, creators, or players, but is needed to test, support, and maintain the game. The full Modding Policy is available online.

A good, friendly server. There are players on the server around the clock who help newcomers or get together for outings. Enough loot spawns since it's x2, but the difficulty is that you need to search for containers that have loot, because players loot often. You won't be bored, since the server has runners, who don't appear all that rarely. Zombies can open doors with a small chance. 1 in-game day lasts 6 hours of real time.

Downsides: the project itself positions itself as an environment for gamers where they can communicate, find friends, or simply play together with people. Even though the project has a chat in Steam, you want something more than just a little chat in Steam. The server has a Discord channel that is only needed for viewing project news. It would be cool to create an environment there for community communication, in addition to the Steam chat group. Add plugins like life of quality to see what's on the server and how, BUT since this is pure vanilla, there's no guarantee they'd even approve something like that.

Bottom line: the project is wonderful, but sometimes there are small problems with ping spikes (more likely DDos attacks)
I wish you a pleasant game on this server!

This server is an entire competition of "who goes the longest without croaking". At first you think that runners and your own stupidity are your main problems, but then you realize, and on your own ass at that, that in this hell there also exist:

1) A fucking chicken that somehow spawned in the city center, gathered a tail of a zombie horde behind it across the whole city and runs straight at you asking to be held.
2) A teammate you can trip over, fall, and die while running with the chicken away from the zombie horde.
3) A teammate who was apparently cursed by Indie Stone for all his sins, and literally every car he touches decides it would be cool to turn on the alarm in the middle of the city.
4) Another teammate who decided that a joke or the thought of offloading a propane tank to another player is betrayal of the highest degree and is punished not only by death but also by losing the claim.
5) A teammate who decided to play Rambo and started blasting with a gun in the city without any plan.
6) Calories are the currency of life. Without callories on this server, it's easy to become anorexic, become slow, and lose your life because of it at the early stage of the game, since clearing a path to even one point of interest is quite a task and consumes an incredible amount of callories. And while your teammate takes away your last pack of chips found in a trash can, you may have to look for other ways to get callories.
7) A fucking plane that appears when you decide to loot around in the city and are forced to sit somewhere in the dark of a house and pray that the hordes running all over the city don't accidentally wander in here.

Yes, more than half of the problems are your teammate and the chicken. Because of this, I have psychological trauma. Now I get anxious when a teammate loads a revolver. I'm scared when a cow moos nearby. I'm scared to think that I have a couple of propane tanks at home...

The Indie Stone has released hotfixes across all three Project Zomboid branches: 42.20.4 Stable, 42.19.2 Unstable, and 41.78.21 Legacy. The update addresses security vulnerabilities and, as part of that fix, removes the Lua loadstring and loadstream methods.

The studio says the update should not break existing saves, but asks players to verify bugs on a fresh save with no mods installed before reporting them to the bug reports forum.

The removal of loadstring and loadstream directly affects mods that relied on these methods. Mod authors must update their work accordingly. If a mod used these methods to execute code sent from a server, the recommended approach is to create the necessary methods and call them by sending the appropriate commands.

Modders who cannot replace these methods should explain their usage in the #mod_portal channel of The Official Project Zomboid Discord server.

Discussion of this update is pinned in the Project Zomboid Steam Discussions.