1.21.4 Nbt crash reports

[FUg123]

Castric NBT data: the server uses custom plugins that modify NBT data (special binary structures for objects and entities). Standard NBT reading types in the Protodef library used by Mineflayer do not cope with such modified or damaged NBT. When you try to read this data, an error occurs, which leads to the connection or disconnection of the bot.
Patches and rounds: in attempts to solve the problem, we tried to patch the internal types of Protodef (for example, to reduce the NBT or slots reading function and replace the version in HANDSHAKE to “deceive” the server. However, such methods either do not work, or require deep refinement and often break during libraries.

What did you try yet?
Running their 1.21.4 example (if available) could confirm whether your environment and network allow connecting normally.
Did you try any example? Any error from those?
We consistently got errors related to NBT parsing or protocol mismatches when running on mismatched versions.
Attempts to patch protodef or mineflayer internals produced runtime errors due to missing or undefined internal types.

const mineflayer = require('mineflayer');
const mc = require('minecraft-data');
const { pathfinder, Movements, goals: { GoalBlock } } = require('mineflayer-pathfinder');

const version = '1.21.4';
const mcData = mc(version);

const bot = mineflayer.createBot({
host: 'mc.terra-enigmatica.ru',
port: 25565,
username: 'FUGA_PSHENICA',
version,
skipValidation: true
});

bot.loadPlugin(pathfinder);

bot.once('spawn', async () => {
console.log('[✅] Бот зашёл на сервер');
await bot.waitForTicks(40);

const defaultMove = new Movements(bot, mcData);
bot.pathfinder.setMovements(defaultMove);

const goal = new GoalBlock(8, 11, 36);
bot.pathfinder.setGoal(goal);
});

bot.on('error', err => {
console.error('[❌] Ошибка соединения:', err);
});

bot.on('end', () => {
console.log('[🔌] Бот отключён от сервера');
});

!!! Some logs for understanding

PartialReadError: Read error for undefined : Missing characters in string, found size is 573 expected size was 614
at new ExtendableError (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\utils.js:63:13)
at new PartialReadError (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\utils.js:70:5)
at Object.string (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :106:15)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :863:77)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :865:17)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :870:15)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :872:13)
at Object.SlotComponent (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :977:9)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :996:49)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :1001:15)
PartialReadError: Read error for undefined : Missing characters in string, found size is 573 expected size was 614
at new ExtendableError (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\utils.js:63:13)
at new PartialReadError (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\utils.js:70:5)
at Object.string (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :106:15)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :863:77)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :865:17)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :870:15)
at eval (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :872:13)
at Object.SlotComponent (eval at compile (C:\Users\Admin\Desktop\mineflayer-4.29.0\node_modules\protodef\src\compiler.js:262:12), :977:9)