Understanding Etherscan Errors Using MetaMask and Smart Contracts
As more and more projects use the Ethereum blockchain, implementing smart contracts is becoming increasingly popular. However, every now and then you come across an error message that can be annoying to deal with. One such issue is encountered by many users when deploying new contracts on the Ethereum network using MetaMask.
In this article, we will find out what the “Invalid Opcode: Opcode 0x4b not defined” warning means and why it occurs. We will also provide some tips on how to resolve this issue and ensure a smooth deployment of smart contracts.
What are Metamask and Etherscan?
MetaMask is a popular web application that allows users to interact with the Ethereum blockchain without having to install a full node setup. It provides a convenient interface for transferring ether (ETH), sending transactions, and verifying block data on the Ethereum network.
Etherscan is a web platform for exploring and analyzing the execution of smart contracts on the Ethereum testnet or mainnet. Using Etherscan, you can view details of all transactions executed on the blockchain, including execution time, gas consumption, and more.
Invalid opcode: Opcode 0x4b undefined error
When a user tries to install a new contract using MetaMask’s “install” function, an error message similar to the following may appear:
Warning! An error occurred during installation.
Invalid opcode: opcode 0x4b is not defined
This warning occurs when the Ethereum Virtual Machine (EVM) detects invalid code in the “install” 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 opcode 0x4b is not defined 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 defined”?
The opcode “0x4b” is a specific instruction that the EVM uses to deploy contracts using the “deploy” function. The most common cause of this error is when the MetaMask “install” function attempts to install a contract that uses an invalid or obsolete transaction code.
Here are some possible reasons for this error:
- Mismatched bytecode
: The deployed contract’s bytecode may not match the expected EVM opcode table.
- Use of invalid transaction code: The contract code may use an invalid or unsupported transaction code that is not recognized by the EVM.
- Malformed “install” function: The MetaMask “install” function may be configured incorrectly, resulting in unexpected behavior during installation.
How to Fix the Error
To resolve the “Invalid opcode: Opcode 0x4b not set” error and successfully deploy a new contract using MetaMask, follow these steps:
- Check the bytecode: Make sure the contract bytecode is compatible with the EVM transaction code table. To generate bytecode for different Ethereum versions, you can use a tool like Truffle or Remix.
- Check the “deploy” function configuration: Review the MetaMask “deploy” function configuration and make sure it is configured correctly 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.