这种错误通常是由于Web3.js的版本问题引起的。要解决此问题，请使用Web3.js v1.2.6或更高版本，并更新您的代码，从而使用toBuffer()而不是toRlp()方法。

以下是一个示例代码：

const Web3 = require('web3');
const web3 = new Web3('http://localhost:8545'); // replace with your network
const BN = web3.utils.BN;

const privateKey = '';
const account = web3.eth.accounts.privateKeyToAccount(privateKey);
const from = account.address;

const contractABI = [];
const contractAddress = '';
const contract = new web3.eth.Contract(contractABI, contractAddress, {from});

const txParams = {
  gasPrice: new BN('20000000000'),
  gasLimit: new BN('350000'),
};

async function transfer() {
  const to = '';
  const amount = new BN('1000000000000000000');

  const data = contract.methods.transfer(to, amount).encodeABI();
  const nonce = await web3.eth.getTransactionCount(from);
  const tx = {
    from,
    to: contractAddress,
    nonce: nonce,
    gasPrice: txParams.gasPrice,
    gasLimit: txParams.gasLimit,
    data: data,
  };

  const signedTx = await web3.eth.accounts.signTransaction(tx, privateKey);
  const txHash = await web3.eth.sendSignedTransaction(signedTx.rawTransaction);
  console.log(`Transaction hash: ${txHash}`);
}

transfer().catch(console.error);