Understanding Etherscan Errors with MetaMask and Smart Contracts
As more and more projects adopt the Ethereum blockchain, deploying smart contracts is becoming increasingly popular. However, every now and then you’ll encounter an error message that can be frustrating to deal with. One such issue is one that many users encounter when deploying new contracts on the Ethereum network using MetaMask.
In this article, we’ll explore what the “Invalid Opcode: Opcode 0x4b not set” warning means and why it occurs. We’ll also provide some tips on how to resolve this issue and ensure a smooth deployment of smart contracts.
What is Metamask and Etherscan?
MetaMask is a popular web application that allows users to interact with the Ethereum blockchain without the need to install a full node setup. It provides a user-friendly interface for transferring Ether (ETH), sending transactions, and verifying block data on the Ethereum network.
Etherscan is a web-based platform for exploring and analyzing the execution of smart contracts on the Ethereum testnet or mainnet. With Etherscan, you can view details of all transactions executed on the blockchain, including their execution time, fuel consumption, and more.
Invalid opcode: Opcode 0x4b undefined error
When a user attempts to deploy a new contract using the MetaMask “deploy” function, an error message similar to the following may appear:
Warning! An error occurred during deployment
Invalid opcode: opcode 0x4b undefined
This warning occurs when the Ethereum Virtual Machine (EVM) detects an invalid code in the “deploy” function. The EVM is responsible for executing instructions on the blockchain, and uses a specific set of opcodes to perform various actions.
In this case, the error message indicates that the opcode 0x4b is undefined in the EVM opcode table. This means that MetaMask attempted to execute an invalid command during the installation process.
What causes the error “Invalid opcode: Opcode 0x4b not set”?
The “0x4b” opcode is a specific instruction that EVM uses to install contracts using the “install” function. The most common cause of this error is when MetaMask’s “install” function attempts to install a contract that uses an invalid or deprecated opcode.
Here are some possible causes for this error:
- Incompatible bytecode: The bytecode of the installed contract may not match the expected EVM opcode table.
- Invalid opcode usage: The contract code may use an invalid or unsupported opcode that the EVM does not recognize.
- Improperly configured “install” function
: The MetaMask “install” function may be configured incorrectly, which may result in unexpected behavior during installation.
How to fix the error
To resolve the error “Invalid opcode: Opcode 0x4b not set” and successfully deploy a new contract using MetaMask, follow these steps:
- Check bytecode: Make sure the contract bytecode is compatible with the EVM opcode table. You can use a tool like Truffle or Remix to generate bytecode for different Ethereum versions.
- Check the “deploy” function configuration: Review the MetaMask “deploy” function configuration and make sure it is properly set up to deploy contracts using the “0x4b” opcode.
- Test with a compatible testnet node: Test the contract deployment on a separate testnet node, such as Rinkeby or Ropsten, to see if the issue persists.
- Update MetaMask and EVM versions: Consider updating your MetaMask and Ethereum Virtual Machine (EVM) versions to the latest stable versions.
After following these steps, you should be able to resolve the “Invalid opcode: Opcode 0x4b not set” error and successfully deploy new contracts using MetaMask on the Ethereum network.