Metamask: [ Web3.js on BSC ]: Returned error: unknown account

Here is a high-quality article about the issue you are facing with Metamask and Web3.js on Binance Smart Chain (BSC):

Error: Unknown account in Web3.js on Binance Smart Chain (BSC)

As a user of decentralized applications (dApps) built on Binance Smart Chain (BSC), you have probably experienced the frustration of encountering errors when interacting with smart contracts. In this article, we will take a deep dive into the issue you are facing and offer a solution to resolve it.

The Problem: “Unknown Account” Error Returned

When you execute a method call on a Metamask-enabled contract using Web3.js on BSC, such as nftMintingContract.methods.mint(account, cid).send({from: account}), the error returned is usually “unknown account”. This error indicates that the transaction failed due to an unknown or unauthorized account being used.

Understanding Account Management in Metamask

In Metamask, accounts are managed as private keys. Each account has a unique key pair (public and private) that is stored in your wallet. When you create an account, it is assigned a public address. However, when you send transactions to the contract using Metamask, the account used is not necessarily the same one you created.

Why the Unknown Account Error Occurs

There are several reasons why this error might appear:

• Different accounts are used: When you execute a method call in a contract using multiple accounts (e.g. from different wallets or with different keys), Metamask treats them as different accounts. This is because each account has its own private key, which is used to sign transactions.

• No Reentrancy Protection: Some contracts may not have Reentrancy Protection enabled in their smart code. This means that if you call the mint method with an unknown account, it can potentially be called multiple times by other accounts (even if they are using different keys), leading to unexpected behavior.

Unknown Account Error Resolution

To resolve this issue, please follow these steps:

• Verify your account

  

  – Make sure your Metamask wallet is properly configured and linked to your BSC account.

• Use a single account for all transactions – When possible, use the same account (public address) for all transactions. This ensures that you always send from the correct account.

• Enable Reentrancy Protection – If your contract does not have Reentrancy Protection enabled, consider enabling it in your smart code to prevent unexpected behavior.

• Use a different account for test transactions – When testing new contracts or features, use a different account (public address) for test transactions.

Code Example

Here is an example of how you can modify your code to resolve the unknown account error:

`javascript

const contract = new Web3.eth.Contract('...');

contract.methods.mint(account, cid).send({from: account})

.then((result) => {

console.log(result); //Mint successful!

})

.catch((error) => {

if (error.code === 'InvalidAccount') {

console.error('Unknown account used for transaction:', error);

} else {

throw error;

}

});

“

If you follow these steps and use a single account for all transactions, you should be able to resolve the “unknown account” error when interacting with Metamask-enabled contracts on BSC.