iBotPeaches/Apktool · error · AndrolibException

Config size < 8

Error message

Config size < 8

What it means

While parsing a ResTable_config (the locale/density/... descriptor of each resource type chunk), the leading `size` field must be at least 8 (uint32 size + mcc + mnc). A smaller declared size means the config header is malformed and cannot even be partially read, so parsing aborts.

Source

Thrown at brut.apktool/apktool-lib/src/main/java/brut/androlib/res/decoder/BinaryResourceParser.java:474

                    if (!mPackage.hasEntrySpec(id, index)) {
                        mPackage.addEntrySpec(id, index, mKeyStringPool.getString(key));
                        mMissingEntrySpecs.remove(resId);
                    }
                    mPackage.addEntry(id, index, config, value);
                }
            }

            // Update the entry count for logging.
            entryCount -= indexes.size();
        }
    }

    private ResConfig parseConfig() throws AndrolibException, IOException {
        long startPosition = mIn.position();
        // ResTable_config
        int size = mIn.readInt();
        if (size < 8) {
            throw new AndrolibException("Config size < 8");
        }

        int mcc = mIn.readUnsignedShort();
        int mnc = mIn.readUnsignedShort();

        String language = "";
        String region = "";
        if (size >= 12) {
            language = unpackLanguageOrRegion(mIn.readBytes(2), 'a');
            region = unpackLanguageOrRegion(mIn.readBytes(2), '0');
        }

        int orientation = 0;
        int touchscreen = 0;
        if (size >= 14) {
            orientation = mIn.readUnsignedByte();
            touchscreen = mIn.readUnsignedByte();
        }

View on GitHub (pinned to 79b63384d7)

Solutions

1. Cross-check with `aapt2 dump resources` / `aapt dump badging` to confirm the config header is genuinely invalid.
2. Fetch a clean copy of the APK and compare the arsc bytes around the reported offset.
3. If you generate arsc files, ensure every ResTable_config is at least 8 bytes (size includes the size field itself).
4. For protected apps, decode the version distributed via a channel that does not apply the resource obfuscator.

try {
    parser.parse(in);
} catch (AndrolibException e) {
    if ("Config size < 8".equals(e.getMessage())) {
        // ResTable_config header corrupt — obtain clean APK
    }
}

When it happens

Trigger: Decoding an arsc whose ResTable_config struct declares size < 8 — corruption of the config header, an arsc produced by a broken/obsessive optimizer, or deliberate fuzzing of config sizes.

Common situations: Resource obfuscation tools (e.g. aggressive arsc shrinkers) that rewrite config headers with wrong sizes; bit-level corruption from bad transfers; experimental arsc generators that don't zero-pad config structs.

Related errors

• Input file is empty.
• Unexpected chunk:
• Could not decode arsc file.
• Missing type string pool.
• Missing key string pool

AI-assisted analysis of iBotPeaches/Apktool@79b63384d7 (2026-08-14). Data as JSON: /api/errors/8ddd03d447ff2a2e. Report an issue: GitHub.