Transaction simulation failed: Blockhash not found

Question

Try to send a transaction using phantom wallet and vuejs.

  import { createUpdateMetadataAccountV2Instruction } from '@metaplex-foundation/mpl-token-metadata';
  import { Transaction } from '@solana/web3.js';

  const updateMetadataAccount = createUpdateMetadataAccountV2Instruction(
    accounts,
    args
  );

  const transaction = new Transaction();
  transaction.add(updateMetadataAccount);
  const { blockhash } = await connection.getLatestBlockhash();
  console.log(blockhash) // "G6NXXgYaPYjpg4StqSMywYb582Rwzsc3pYXWKJbRcNoA"
  transaction.recentBlockhash = blockhash;
  transaction.feePayer = wallet.publicKey;
  const signature = await wallet.signAndSendTransaction(transaction)

I got this error: RPC Error: failed to send transaction: Transaction simulation failed: Blockhash not found

Answer 1

A call to connection.getLatestBlockhash() will retrieve a blockhash from the RPC node you have configured in connection, at the commitment level in connection. This blockhash is then used in the transaction that is forwarded to the leader when you send the transaction.

There are two cases that can cause a Blockhash not found error:

1. The retrieved blockhash ended up being on a minority fork of the network and the leader does not consider it valid - or the RPC node later drops it as a minority fork. Avoid this by using getLatestBlockhash('finalized'), which will give you a blockhash that has been finalized by the network.

-or-

2. Enough time has passed between your call to getLatestBlockhash() and sending the transaction that the network has moved on and the blockhash is now too old. Avoid this by only retrieving the blockhash when it's time to send.

Here is a lot more words on the subject of transaction confirmation: https://jstarry.notion.site/Transaction-confirmation-d5b8f4e09b9c4a70a1f263f82307d7ce

Answer 2

I think is worth mentioning because is such a common mistake, that you will also see this error when a web3 app is connected to Mainnet but the network of your Phantom wallet is switched to Devnet (or the other way around)