I am running a contract on a private network in geth, and using web3js. I have the following error when I run a transaction:

web3.min.js:1 Uncaught (in promise) Error: Returned error: gas required exceeds allowance (89459648255865) or always failing transaction

Here is my contract in solidity:

contract Voting {
  /* mapping field below is equivalent to an associative array or hash.
  The key of the mapping is candidate name stored as type bytes32 and value is
  an unsigned integer to store the vote count

  mapping (bytes32 => uint256) public votesReceived;

  /* Solidity doesn't let you pass in an array of strings in the constructor (yet).
  We will use an array of bytes32 instead to store the list of candidates

  bytes32[] public candidateList;

  /* This is the constructor which will be called once when you
  deploy the contract to the blockchain. When we deploy the contract,
  we will pass an array of candidates who will be contesting in the election
  constructor(bytes32[] memory candidateNames) public {
    candidateList = candidateNames;

  // This function returns the total votes a candidate has received so far
  function totalVotesFor(bytes32 candidate) view public returns (uint256) {
    return votesReceived[candidate];

  // This function increments the vote count for the specified candidate. This
  // is equivalent to casting a vote
  function voteForCandidate(bytes32 candidate) public {
    votesReceived[candidate] += 1;

  function validCandidate(bytes32 candidate) view public returns (bool) {
    for(uint i = 0; i < candidateList.length; i++) {
      if (candidateList[i] == candidate) {
        return true;
    return false;

And my index.js that I call from a index.html file to use it:

web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"))
var account;
web3.eth.getAccounts().then((f) => {
 account = f[0];

abi = JSON.parse('[{"constant":true,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"totalVotesFor","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"validCandidate","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"bytes32"}],"name":"votesReceived","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"candidateList","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"candidate","type":"bytes32"}],"name":"voteForCandidate","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"candidateNames","type":"bytes32[]"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"}]')

contract = new web3.eth.Contract(abi);
contract.options.address = "0x71789831d83d4C8325b324eA9B5fFB27525480b5";
// update this contract address with your contract address

candidates = {"Rama": "candidate-1", "Nick": "candidate-2", "Jose": "candidate-3"}

function voteForCandidate(candidate) {
 candidateName = $("#candidate").val();

 contract.methods.voteForCandidate(web3.utils.asciiToHex(candidateName)).send({from: account}).then((f) => {
  let div_id = candidates[candidateName];
  contract.methods.totalVotesFor(web3.utils.asciiToHex(candidateName)).call().then((f) => {
   $("#" + div_id).html(f);

$(document).ready(function() {
 candidateNames = Object.keys(candidates);

 for(var i=0; i<candidateNames.length; i++) {
 let name = candidateNames[i];

 contract.methods.totalVotesFor(web3.utils.asciiToHex(name)).call().then((f) => {
  $("#" + candidates[name]).html(f);

Can somebody help me please ? I am pretty new to this. Thank you

  • Which function are you calling? What the parameters did you use? – Ismael Mar 25 at 20:09
  • I am calling VoteForCandidate for 'rama' , it is working on ganache but not on geth, thanks – oklm Mar 25 at 22:28
  • What version of solc are you using to compile? Are you testing against a public testnet or private testnet? Do you have the new opcodes from constantinople enabled? – Ismael Mar 25 at 23:13
  • solc 0.5.16 on a private network on geth. No new opcodes enables i think – oklm Mar 26 at 8:30

If someone has the same problem, the solution was to specify the amount of gas that I want for the transaction in the code, hope that will help someone :)

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