[The IPFS link to see source code] (http://dweb.link/ipfs/QmVcFrLDPrEY8sveEdXnib6etMtes8z12GsNo21vbfdtiv) The error I got when try to deploy SAFEMARS contract : creation of SAFEMARS errored: Cannot convert undefined or null to object Solidity version : ^0.6.12

  • I am new with smart contract development, thank you in advance for any help
    – Antonio
    Apr 21, 2021 at 21:15
  • What error did you get? Please add more details what was tried and failed, tools, or solidity versions used. Asking for help and just dumping code isn't nice.
    – Ismael
    Apr 21, 2021 at 23:59
  • Thanks with your great suggest ! This error is " Cannot convert undefined or null to object "
    – Antonio
    Apr 22, 2021 at 10:17
  • I tried to deploy a flatter solidity file with multiple contracts into single contract, but always got error like above
    – Antonio
    Apr 22, 2021 at 10:20

2 Answers 2


I see your code and the contract SAFEMARS depends on the IUniswapV2Router02 contract at the address 0x05fF2B0DB69458A0750badebc4f9e13aDd608C7F. I guess maybe you should have to create the IUniswapV2Router02 contract first, then deploy this SAFEMARS contract.

    constructor () public {
    _rOwned[_msgSender()] = _rTotal;

    // maybe lack of this contract? i guess
    IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x05fF2B0DB69458A0750badebc4f9e13aDd608C7F);
    // Create a uniswap pair for this new token
    uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory())
    .createPair(address(this), _uniswapV2Router.WETH());

    // set the rest of the contract variables
    uniswapV2Router = _uniswapV2Router;

    //exclude owner and this contract from fee
    _isExcludedFromFee[owner()] = true;
    _isExcludedFromFee[address(this)] = true;

    emit Transfer(address(0), _msgSender(), _tTotal);
  • I am doing on it, thank you very much
    – Antonio
    Apr 22, 2021 at 10:26
  • I am doing on test net of binance smart chain, so this address "0x05fF2B0DB69458A0750badebc4f9e13aDd608C7 " is PancakeRouter on mainnet, so I changed it into this address "0xD99D1c33F9fC3444f8101754aBC46c52416550D1" - is PancakeRouter on test net of Binance Smart Chain. Still not works, sorry
    – Antonio
    Apr 22, 2021 at 10:36

Would suggest you to use solidity flattener or hardhat flattener, and then compile and deploy the file from remix for a start should work if there are no compilation errirs

  • Actually, it is flattener solidity file, I have compiled it without error. only problem with deploy
    – Antonio
    Apr 22, 2021 at 10:25
  • would recommend then you first try deploying through remix
    – viraj
    Apr 22, 2021 at 11:02

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