Anuken/Mindustry · error · ArcRuntimeException

Too many long strings in MenuResult, reduce your amount of e

Error message

Too many long strings in MenuResult, reduce your amount of elements/IDs.

What it means

readMenuResult() enforces a global character budget (MenuResult.maxTotalStringLen = 6000) shared across all keys and string values. Before reading each key it checks remainingChars <= 0 and throws. This bounds total string memory per menu result.

Source

Thrown at core/src/mindustry/io/TypeIO.java:327

    public static MenuResult readMenuResult(Reads read){
        MenuResult result = new MenuResult();

        result.token = read.l();

        //would be nice to count bytes but sadly that's not really viable here
        int remainingChars = MenuResult.maxTotalStringLen;

        byte exists = read.b();
        if(exists != 0){
            result.result = read.str(MenuResult.maxResultLen);
            remainingChars -= result.result.length();
        } //else, no result, remains null

        int entries = read.us();
        if(entries > MenuResult.maxTotalValues) throw new ArcRuntimeException("UI result entry count exceeds max entries: " + entries);

        for(int i = 0; i < entries; i++){
            if(remainingChars <= 0) throw new ArcRuntimeException("Too many long strings in MenuResult, reduce your amount of elements/IDs.");
            String key = read.str(Math.min(remainingChars, MenuResult.maxValueLen));
            remainingChars -= key.length();

            byte type = read.b();

            switch(type){
                case 0 -> result.values.put(key, read.f());
                case 1 ->  result.values.put(key, read.bool());
                case 2 -> {
                    if(remainingChars <= 0) throw new ArcRuntimeException("Too many long strings in MenuResult, reduce your amount of elements/IDs.");
                    String value = read.str(Math.min(remainingChars, MenuResult.maxValueLen));
                    remainingChars -= value.length();
                    result.values.put(key, value);
                }
                default -> throw new ArcRuntimeException("Unknown UI entry type: " + type);
            }
        }
        return result;

View on GitHub (pinned to f695ad7e60)

Solutions

  1. Shorten keys and reduce the number of entries so total chars stay under 6000.
  2. Use compact key names in the UI builder.
Defensive patterns

Strategy: validation

Validate before calling

// Budget total key characters before sending a menu result.
int total = 0;
for(var k : menuResult.values.keys()) total += k.length();
if(total > MenuResult.maxTotalStringLen){
    throw new IllegalStateException("Menu keys too long: " + total);
}

Try / catch

try { MenuResult r = TypeIO.readMenuResult(read); }
catch(ArcRuntimeException e){ Log.err("Bad menu result", e); con.kick("Invalid menu result."); }

Prevention

When it happens

Trigger: The cumulative length of menu-result keys (plus any prior strings) reaches or exceeds 6000 chars before a key is read.

Common situations: A menu with many or long element IDs/keys; a mod generating verbose keys; a malicious client.

Related errors

AI-assisted analysis of Anuken/Mindustry@f695ad7e60 (2026-08-14). Data as JSON: /api/errors/21d17e12ae393f41. Report an issue: GitHub.