PartialReadError and chunk inflation error

• The FAQ doesn't contain a resolution to my issue

Versions

• mineflayer: 4.37.1
• server: Hypixel SkyBlock (ViaVersion proxy translating 1.8.9 -> 1.21.11)
• node: 22.13.1

Detailed description of a problem

When connecting to Hypixel SkyBlock using mineflayer on version 1.21.11 (or 1.21.4), the bot successfully authenticates and spawns into the main lobby. However, upon switching to the SkyBlock server (/play skyblock), minecraft-protocol encounters chunk decompression errors (problem inflating chunk).

Because the chunks fail to decompress properly, the TCP stream desynchronizes. This results in protodef continuously throwing PartialReadError: Read error for undefined as it misinterprets the remaining stream bytes as garbage packets (e.g., firing tile_entity_data or block_action with malformed f32 or NBT data). The connection enters an infinite loop of these read errors, and bot.world never populates, causing bot.blockAt() to always return null.

I am building a bot to scan a player's Garden on SkyBlock to log specific crop mutation blocks. Without chunk loading, bot.blockAt() does not work, and the bot cannot read the layout.

What did you try yet?

• Tested 1.20.4 and 1.21.1: Hypixel actively kicks the bot on login with "Your version of Minecraft cannot be used to play on Hypixel."
• Tested 1.21.4 and 1.21.11: The bot connects and bypasses the version check, but chunk inflation fails immediately when entering SkyBlock.
• Tested disabling physics (physicsEnabled: false) to see if Mineflayer's collision logic was triggering the crash. The issue persists because it occurs natively within the minecraft-protocol packet parser before physics even handles the chunks.

Your current code

const mineflayer = require('mineflayer');

const bot = mineflayer.createBot({
    host: 'mc.hypixel.net',
    version: '1.21.11',
    auth: 'microsoft',
    username: '(Email)'
});

bot.once('spawn', () => {
    // Navigates to SkyBlock after a short delay to trigger the chunk streaming
    setTimeout(() => {
        bot.chat('/play skyblock');
    }, 8000);
});

Expected behavior

minecraft-protocol and prismarine-chunk should successfully decompress and parse the 1.21.11 ViaVersion translated chunks sent by Hypixel's proxy, allowing bot.world to populate.

Additional context

Initial Decompression Failure:

problem inflating chunk
uncompressed length 3159
compressed length 466
hex d718789cadd55d4f...

Subsequent Stream Desynchronization (Infinite Loop):

PartialReadError: Read error for undefined : undefined
    at new ExtendableError (node_modules\protodef\src\\\utils.js:63:13)
    at new PartialReadError (node_modules\protodef\src\\\utils.js:70:5)
    at Object.reader [as f32] (node_modules\protodef\src\datatypes\numeric.js:89:48)
    at eval (eval at compile (node_modules\protodef\src\compiler.js:262:12), <anonymous>:1166:60)
    at Object.packet_world_particles (eval at compile (node_modules\protodef\src\compiler.js:262:12), <anonymous>:2600:67)
    at CompiledProtodef.read (node_modules\protodef\src\compiler.js:70:12)

Dependencies:

• minecraft-protocol: 1.66.2
• prismarine-chunk: 1.40.0