Error: cannot estimate gas; transaction may fail or may require manual gas limit

[mazen-sleem]

when I try to apply lesson 5 with Rinkeby network

I have an error say (Error: cannot estimate gas; transaction may fail or may require manual gas limit)

how to solve it?

[alymurtazamemon]

@mazen-sleem There could be many reasons for it, need more clarification.

Please follow this guide next time when you ask a question. How to Ask Question Guide

[mazen-sleem]

this is the code :

const ethers = require("ethers")

const fs = require("fs-extra")
require("dotenv").config()

async function main() {
  
    let provider = new ethers.providers.JsonRpcProvider(process.env.RPC_URL)
    
    const encryptedJson = fs.readFileSync("./.encryptedKey.json", "utf8");
    let wallet = new ethers.Wallet.fromEncryptedJsonSync(
      encryptedJson,
      process.env.PRIVATE_KEY_PASSWORD
    );
    wallet = wallet.connect(provider);
    const abi = fs.readFileSync("./SimpleStorage_sol_SimpleStorage.abi", "utf8")
    const binary = fs.readFileSync(
        "./SimpleStorage_sol_SimpleStorage.bin",
        "utf8"
    )
    const contractFactory = new ethers.ContractFactory(abi, binary, wallet)
    console.log("Deploying, please wait...")
    const contract = await contractFactory.deploy()
   
    const deploymentReceipt = await contract.deployTransaction.wait(1)
    console.log(`Contract deployed to ${contract.address}`)


  

    let currentFavoriteNumber = await contract.retrieve()
    console.log(`Current Favorite Number: ${currentFavoriteNumber}`)
    console.log("Updating favorite number...")
    let transactionResponse = await contract.store(7)
    let transactionReceipt = await transactionResponse.wait()
    currentFavoriteNumber = await contract.retrieve()
    console.log(`New Favorite Number: ${currentFavoriteNumber}`)
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error)
        process.exit(1)
    })

and the error is : Error: cannot estimate gas; transaction may fail or may require manual gas limit [ See: https://links.ethers.org/v5-errors-UNPREDICTABLE_GAS_LIMIT ]

[mazen-sleem]

@alymurtazamemon is it ok right now ?

[mazen-sleem]

I found the error
so thank you @alymurtazamemon for your time

[Sunil-Reddy-Gummalla]

Hi @mazen-sleem pls write what is that error below and Make this Question as Answered So that Others With Same Question Will find it easily

[mazen-sleem]

this is the correct code :

const ethers = require("ethers")

const fs = require("fs-extra")
require("dotenv").config()

async function main() {
  
 let provider = new ethers.providers.JsonRpcProvider(process.env.RPC_URL)
    let wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider)
    
    const abi = fs.readFileSync("./SimpleStorage_sol_SimpleStorage.abi", "utf8")
    const binary = fs.readFileSync(
        "./SimpleStorage_sol_SimpleStorage.bin",
        "utf8"
    )
    const contractFactory = new ethers.ContractFactory(abi, binary, wallet)
    console.log("Deploying, please wait...")
    const contract = await contractFactory.deploy()
   
    const deploymentReceipt = await contract.deployTransaction.wait(1)
    console.log(`Contract deployed to ${contract.address}`)


  

    let currentFavoriteNumber = await contract.retrieve()
    console.log(`Current Favorite Number: ${currentFavoriteNumber}`)
    console.log("Updating favorite number...")
    let transactionResponse = await contract.store(7)
    let transactionReceipt = await transactionResponse.wait()
    currentFavoriteNumber = await contract.retrieve()
    console.log(`New Favorite Number: ${currentFavoriteNumber}`)
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error)
        process.exit(1)
    })

as I removed this part

 
 const encryptedJson = fs.readFileSync("./.encryptedKey.json", "utf8");
     let wallet = new ethers.Wallet.fromEncryptedJsonSync(
       encryptedJson,
       process.env.PRIVATE_KEY_PASSWORD
    );
   wallet = wallet.connect(provider);

replaced it with
let wallet = new ethers.Wallet(process.env.PRIVATE_KEY, provider)