Metamask: invalid opcode: opcode 0x4b not defined when sending a new contract

Understanding Etherscan Errors with MetaMask and Smart Contracts

As a growing number of projects take advantage of the Ethereum blockchain, deploying smart contracts becomes increasingly popular. However, every now and then, you encounter an error message that can be frustrating to deal with. One such issue is encountered by many users when using MetaMask for deploying new contracts on the Ethereum network.

In this article, we’ll explore what the Invalid opcode: opcode 0x4b not defined warning means and why it occurs. We’ll also provide some tips on how to resolve this issue and ensure a smooth experience with your smart contract deployments.

What is Metamask and Etherscan?

MetaMask is a popular web application that allows users to interact with the Ethereum blockchain without needing to install an entire full Node setup. It provides a user-friendly interface for transferring Ether (ETH), sending transactions, and inspecting block data on the Ethereum network.

Etherscan is a web-based platform for exploring and analyzing smart contract executions on the Ethereum testnet or mainnet. With Etherscan, you can view the details of all transactions executed on the blockchain, including their execution time, gas costs, and more.

Invalid Opcode: Opcode 0x4b Not Defined Error

When a user tries to deploy a new contract using MetaMask’s deploy function, they may encounter an error message similar to this:

Warning! Error encountered during deployment

Invalid opcode: opcode 0x4b not defined

This warning occurs when the Ethereum Virtual Machine (EVM) encounters an invalid opcode for the deploy function. The EVM is responsible for executing instructions on the blockchain, and it uses a specific set of opcodes to perform various actions.

In this case, the error message indicates that the 0x4b opcode is not defined in the EVM’s opcode table. This means that MetaMask has attempted to execute an invalid instruction during the deployment process.

What Causes the Invalid Opcode: Opcode 0x4b Not Defined Error?

The 0x4b opcode is a specific instruction used by the EVM for deploying contracts using the deploy function. The most common reason for encountering this error is when MetaMask’s deploy function attempts to deploy a contract that uses an invalid or deprecated opcode.

Here are some possible causes of this error:

• Incompatible bytecode: The deployed contract’s bytecode may not match the EVM’s expected opcode table.

• Invalid opcode usage: The contract’s code might use an invalid or unsupported opcode, which is not recognized by the EVM.

• Misconfigured deploy function

  : MetaMask’s deploy function may be configured incorrectly, leading to unexpected behavior during deployment.

How to Resolve the Error

To resolve the Invalid Opcode: Opcode 0x4b Not Defined error and successfully deploy your new contract using MetaMask, follow these steps:

• Verify the bytecode: Ensure that your contract’s bytecode is compatible with the EVM’s opcode table. You can use a tool like Truffle or Remix to generate bytecode for different Ethereum versions.

• Check the deploy function configuration: Review MetaMask’s deploy function configuration and ensure that it is set up correctly to deploy contracts using the 0x4b opcode.

• Test with a compatible testnet node

  : Test your contract deployment on a separate testnet node, such as Rinkeby or Ropsten, to validate that the issue persists.

• Upgrade MetaMask and EVM versions: Consider upgrading your MetaMask and Ethereum Virtual Machine (EVM) versions to the latest stable releases.

By following these steps, you should be able to resolve the Invalid Opcode: Opcode 0x4b Not Defined error and successfully deploy new contracts using MetaMask on the Ethereum network.

SOLANA BEST