Anuken/Mindustry · error · IllegalArgumentException

Mod is not loaded yet (or missing)!

Error message

Mod is not loaded yet (or missing)!

What it means

Mods.getConfigFolder maps a Mod instance to its ModMeta via the metas registry. If no meta is registered for that mod class, it means the mod has not finished loading/registration yet, and an IllegalArgumentException is thrown. getConfig() delegates here.

Source

Thrown at core/src/mindustry/mod/Mods.java:71

    Seq<LoadedMod> mods = new Seq<>();
    private Seq<LoadedMod> newImports = new Seq<>();
    private ObjectMap<Class<?>, ModMeta> metas = new ObjectMap<>();
    private boolean requiresReload;

    public Mods(){
        Events.on(ClientLoadEvent.class, e -> Core.app.post(this::checkWarnings));
    }

    /** @return the main class loader for all mods */
    public ClassLoader mainLoader(){
        return mainLoader;
    }

    /** @return the folder where configuration files for this mod should go. Call this in init(). */
    public Fi getConfigFolder(Mod mod){
        ModMeta load = metas.get(mod.getClass());
        if(load == null) throw new IllegalArgumentException("Mod is not loaded yet (or missing)!");
        Fi result = modDirectory.child(load.name);
        result.mkdirs();
        return result;
    }

    /** @return a file named 'config.json' in the config folder for the specified mod.
     * Call this in init(). */
    public Fi getConfig(Mod mod){
        return getConfigFolder(mod).child("config.json");
    }

    /** Returns a list of files per mod subdirectory. */
    public void listFiles(String directory, Cons2<LoadedMod, Fi> cons){
        eachEnabled(mod -> {
            Fi file = mod.root.child(directory);
            if(file.exists()){
                for(Fi child : file.list()){
                    if(!child.isDirectory()){

View on GitHub (pinned to f695ad7e60)

Solutions

1. Move all getConfig()/getConfigFolder() calls into the mod's init() method (documented requirement).
2. Ensure you call getConfig on the actual loaded Mod instance, not a fresh one.
3. Do not access config during class construction or static init.

Example fix

// before
public class MyMod extends Mod {
    public MyMod() {
        Fi cfg = getConfig(); // throws: not loaded yet
    }
}

// after
public class MyMod extends Mod {
    @Override
    public void init() {
        Fi cfg = getConfig();
    }
}

// Only fetch config once the mod is registered.
if(!mods.getMods().anyMatch(m -> m.main == this)) {
    throw new IllegalStateException("getConfig called before mod registration; move to init().");
}
Fi cfg = getConfig();

try {
    Fi cfg = getConfig();
} catch(IllegalArgumentException e) {
    if(e.getMessage().equals("Mod is not loaded yet (or missing)!")) { /* defer to init() */ }
    else throw e;
}

When it happens

Trigger: A mod calls getConfigFolder/getConfig from its constructor or any callback that runs before the mod is registered in the metas map.

Common situations: Mod reads config in its constructor instead of init(); plugin instantiated outside the normal load flow; calling getConfig on a mod object that is not the loaded instance.

Related errors

• Calling getPixmap outside of createIcons is not supported!
• Error loading mod {mod.meta.name}
• No constructor set up for unit '@': Assign `constructor = [y
• No constructor set up for unit '{name}', add this argument t
• Two content objects defined with the same name: '{content.na

AI-assisted analysis of Anuken/Mindustry@f695ad7e60 (2026-08-14). Data as JSON: /api/errors/cd2d6205cf157218. Report an issue: GitHub.