I have created a smart contract to issue an ERC20 token, but when I try to send the token from one address to another I get a "Warning! Error encountered during contract execution [Bad instruction]" message on etherscan.io. The token is already created and the contract is validated.
Also, I´m able to send tokens from the address holding the tokens but once I try to send from a receiver address, I get the error.
You can see the failed transactions here.
Your contract has a bug
/* Internal transfer, only can be called by this contract */ function _transfer(address _from, address _to, uint _value) internal { require (_to != 0x0); // Prevent transfer to 0x0 address. Use burn() instead require (balanceOf[_from] > _value); // Check if the sender has enough require (balanceOf[_to] + _value > balanceOf[_to]); // Check for overflows balanceOf[_from] -= _value; // Subtract from the sender balanceOf[_to] += _value; // Add the same to the recipient Transfer(_from, _to, _value); } It will not allow to transfer the full amount of tokens, it has to be strictly less. Instead of 12000, try 11999.
You have to modify your contract to
require (balanceOf[_from] >= _value); 