Thu Dec 27 2018 11:08:38 GMT+0800 (中国标准时间) 

VM256:5 Cannot read property 'first_column' of undefined

(anonymous) @ VM256:5

(function(){

    delete this.nw;

    this.chrome = null

  })();console.group("Thu Dec 27 2018 11:08:38 GMT+0800 (中国标准时间) ")

        console.error("Cannot read property 'first_column' of undefined")

      console.groupEnd()