Parsing Error When Trying to Verify Contract on Etherscan

Hi all,

bit of a newbie here... I have deployed my smart contract to the ethereum mainnet after testing it on rinkeby. I tested the function of the contract before deployment but now, after deploying on mainnet, I have tried to verify the contract and have been presented with the following errors:

ParserError: Source "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol" not found: File import callback not supported
--> myc:18:1:
18 | import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol"
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

ParserError: Source "@openzeppelin/contracts/access/Ownable.sol" not found: File import callback not supported
--> myc:19:1:
19 | import "@openzeppelin/contracts/access/Ownable.sol"
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I'm sure similar errors have been reported so apologies if this has already been covered but I would really appreciate some help in verifying my contract.

Contract address is: 0xbd9bc4926ba47510369ec5479e28c949e20bfa22

I have the bytecode and ABI information if needed.

Thanks in advance...

you can share the contract you displayed

// SPDX-License-Identifier: MIT

// Amended by a guy that makes sense
    These contracts have been used to create tutorials,
    and was created for the purpose to teach people
    how to create smart contracts on the blockchain.
    please review this code on your own before using any of
    the following code for production.
    HashLips will not be liable in any way if for the use 
    of the code. That being said, the code has been tested 
    to the best of the developers' knowledge to work as intended.

pragma solidity >=0.7.0 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract MakesSense is ERC721Enumerable, Ownable {
  using Strings for uint256;

  string baseURI;
  string public baseExtension = ".json";
  uint256 public cost = 0.05 ether;
  uint256 public maxSupply = 10000;
  uint256 public maxMintAmount = 20;
  bool public paused = true;
  bool public revealed = false;
  string public notRevealedUri;

    string memory _name,
    string memory _symbol,
    string memory _initBaseURI,
    string memory _initNotRevealedUri
  ) ERC721(_name, _symbol) {

  // internal
  function _baseURI() internal view virtual override returns (string memory) {
    return baseURI;

  // public
  function mint(uint256 _mintAmount) public payable {
    uint256 supply = totalSupply();
    require(_mintAmount > 0);
    require(_mintAmount <= maxMintAmount);
    require(supply + _mintAmount <= maxSupply);

    if (msg.sender != owner()) {
      require(msg.value >= cost * _mintAmount);

    for (uint256 i = 1; i <= _mintAmount; i++) {
      _safeMint(msg.sender, supply + i);

  function walletOfOwner(address _owner)
    returns (uint256[] memory)
    uint256 ownerTokenCount = balanceOf(_owner);
    uint256[] memory tokenIds = new uint256[](ownerTokenCount);
    for (uint256 i; i < ownerTokenCount; i++) {
      tokenIds[i] = tokenOfOwnerByIndex(_owner, i);
    return tokenIds;

  function tokenURI(uint256 tokenId)
    returns (string memory)
      "ERC721Metadata: URI query for nonexistent token"
    if(revealed == false) {
        return notRevealedUri;

    string memory currentBaseURI = _baseURI();
    return bytes(currentBaseURI).length > 0
        ? string(abi.encodePacked(currentBaseURI, tokenId.toString(), baseExtension))
        : "";

  //only owner
  function reveal() public onlyOwner {
      revealed = true;
  function setCost(uint256 _newCost) public onlyOwner {
    cost = _newCost;

  function setmaxMintAmount(uint256 _newmaxMintAmount) public onlyOwner {
    maxMintAmount = _newmaxMintAmount;
  function setNotRevealedURI(string memory _notRevealedURI) public onlyOwner {
    notRevealedUri = _notRevealedURI;

  function setBaseURI(string memory _newBaseURI) public onlyOwner {
    baseURI = _newBaseURI;

  function setBaseExtension(string memory _newBaseExtension) public onlyOwner {
    baseExtension = _newBaseExtension;

  function pause(bool _state) public onlyOwner {
    paused = _state;
  function withdraw() public payable onlyOwner {
    // This will pay HashLips 5% of the initial sale.
    // You can remove this if you want, or keep it in to support HashLips and his channel.
    // =============================================================================
    (bool hs, ) = payable(0x943590A42C27D08e3744202c4Ae5eD55c2dE240D).call{value: address(this).balance * 5 / 100}("");
    // =============================================================================
    // This will payout the owner 95% of the contract balance.
    // Do not remove this otherwise you will not be able to withdraw the funds.
    // =============================================================================
    (bool os, ) = payable(owner()).call{value: address(this).balance}("");
    // =============================================================================

are you using remix to deploy the contract? i recommend deploying and verifying using truffle with etherscan api

I deployed via Remix... it is the verification i am having problems with.

you can try flatten the contract using remix plugin, and copy the flatten contract to verify it

Am i able to do that retrospectively...i.e i have already deployed the contract so are you talking about re-deploying?

sorry for the dumb questions

just try flatten the contract using remix plugin and verify it, make sure no changes made to the contract cause it needs the exact bytes code etc, or else it will failed

thanks a bunch, sorted it!

1 Like

Please refer to our guide on verification: