【Solidity】Gas estimation failed-Gas estimation errored with the following message

今天在写完合约在remix部署测试的时候遇到了这么一个问题，一旦向合约里写数据就出现如下错误：
Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending?
如下图所示：

网上一直搜索不到解决方法，最后经过自己的一番折腾后，还是解决了！
先说一下想实现的功能，尝试用合约存储四六级成绩，因为可以多次参加考试，所以每个人可以有多次四六级成绩记录。
原先合约代码：

pragma solidity ^0.4.23;
import "./Ownable.sol";
contract StudentFactory is Ownable{
    struct CET4{
        uint32 time; 
        uint32 grade;
    }

    struct CET6{
        uint32 time; 
        uint32 grade;
    }
    mapping (address=>CET4[]) public addrToCET4; 
    mapping (address=>CET6[]) public addrToCET6;
    mapping (address=>uint) public addrCET4Count; 
    mapping (address=>uint) public addrCET6Count; 
}

contract StudentHelper is StudentFactory{
    function addCET4To(address _addr,uint32 _time,uint32 _grade) public onlyOwner{
        CET4[] storage CET4List = addrToCET4[_addr]; 
        CET4List[CET4List.length] = CET4(_time,_grade);
        addrCET4Count[_addr]++;
    }

    function addCET6To(address _addr,uint32 _time,uint32 _grade) public onlyOwner{
        CET6[] storage CET6List = addrToCET6[_addr]; 
        CET6List[CET6List.length] = CET6(_time,_grade);
        addrCET6Count[_addr]++;
    }
}

虽然编译没问题，但是一旦调用addCET4To来写入成绩的时候就会出现Gas estimation failed的ERROR，根据字面意思看是因为计算不出来所需GAS的费用，即使强制执行transaction也会失败，博主也是小白，推测是GAS开销太大了导致的问题，期待有哪位大佬能出详细的原因解释。

后来博主改变了思路，引入了CET4List和CET6List来存储成绩列表，并使mapping (address=>CET4[]) public addrToCET4和mapping (address=>CET6[]) public addrToCET6变为mapping (uint=>address) internal CET4IndexToAddr和mapping (uint=>address) internal CET6IndexToAddr。
先通过for循环找出符合地址的CET4[]和CET6[]的索引，再用索引去访问数组中具体的成绩。合约代码如下所示：

pragma solidity ^0.4.23;
import "./Ownable.sol";
contract StudentFactory is Ownable{
    struct CET4{
        uint32 time; 
        uint32 grade;
    }

    struct CET6{
        uint32 time; 
        uint32 grade;
    }
    CET4[] CET4List; // 四级成绩列表
    CET6[] CET6List; // 六级成绩列表
    mapping (uint=>address) internal CET4IndexToAddr; // 四级成绩序号到地址的映射
    mapping (uint=>address) internal CET6IndexToAddr; // 六级成绩序号到地址的映射
    mapping (address=>uint) public addrCET4Count; 
    mapping (address=>uint) public addrCET6Count; 
}

contract StudentHelper is StudentFactory{
    // 给某个地址添加四级成绩记录
    function addCET4To(address _addr,uint32 _time,uint32 _grade) public onlyOwner{
        uint index = CET4List.push(CET4(_time,_grade))-1;
        CET4IndexToAddr[index] = _addr;
        addrCET4Count[_addr]++;
    }

    // 给某个地址添加六级成绩记录
    function addCET6To(address _addr,uint32 _time,uint32 _grade) public onlyOwner{
        uint index = CET6List.push(CET6(_time,_grade))-1;
        CET6IndexToAddr[index] = _addr;
        addrCET6Count[_addr]++;
    }

    // 获得某个地址的四级成绩
    function getCET4ByAddr(address _addr) view public returns (uint32[],uint32[]) {
        uint32[] memory timeList = new uint32[](addrCET4Count[_addr]); 
        uint32[] memory gradeList = new uint32[](addrCET4Count[_addr]);
        uint counter = 0;    
        for (uint i = 0; i < CET4List.length; i++) {
            if(CET4IndexToAddr[i]==_addr){
                timeList[counter] = CET4List[i].time;
                gradeList[counter] = CET4List[i].grade;
                counter++;
            }
        }
        return(timeList,gradeList);
    }

    // 获得某个地址的六级成绩
    function getCET6ByAddr(address _addr) view public returns (uint32[],uint32[]) {
        uint32[] memory timeList = new uint32[](addrCET6Count[_addr]); 
        uint32[] memory gradeList = new uint32[](addrCET6Count[_addr]);
        uint counter = 0;    
        for (uint i = 0; i < CET6List.length; i++) {
            if(CET6IndexToAddr[i]==_addr){
                timeList[counter] = CET6List[i].time;
                gradeList[counter] = CET6List[i].grade;
                counter++;
            }
        }
        return(timeList,gradeList);
    }
}

问题解决～