I'm using the crowdsale contract (https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/crowdsale/Crowdsale.sol). I have deployed a detailedERC20 smart contract. When I send the ether to the crowdsale contract it shows me the following error: SafeERC20: low-level call failed
When I use transfer() externally it works fine.
computer Environment Ganache-cli