I have deployed the both the contracts from Remix ,used the compiler 0.5.17 and Flatten with Truffle in Ubuntu18.
My Crowdsale contract address is 0x8599820a642ef194a7119bd9442b3882f3a37cb0 on the real net
Code Used
pragma solidity ^0.5.0;
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.5.0/contracts/crowdsale/Crowdsale.sol";
/**
@title YieldCrowdsale
@dev This is an example of a fully fledged crowdsale.
*/contract YieldCrowdsale is Crowdsale {
constructor (
uint256 rate,
address payable wallet,
IERC20 token
)
public
Crowdsale(rate, wallet, token)
{
}
}
The contract has constructor arguments so we need to supply them when verifying. Etherscan provides them so just needed to cut out the text before the 0000...00028