命令行warning(Emitted value instead of an instance of Error)。component lists rendered with v-for should have explicit keys。See https://vuejs.org/guide/list.html#key for more info.
截图如下：

这里只是推荐使用key.
原本的代码如下：

          <el-tag
            v-for = "feiLei of ruleForm.fenLeis"          
            :closable = "true"
            type = "primary"
            @close = "handleCloseFenLei(feiLei)">{{feiLei.name}}
          </el-tag>

运行时显示warning，添加：key即可，如下：

          <el-tag
            v-for = "feiLei of ruleForm.fenLeis"
            :key="feiLei1"        
            :closable = "true"
            type = "primary"
            @close = "handleCloseFenLei(feiLei)">{{feiLei.name}}
          </el-tag>

这样就不会报错啦，具体看文档，key不是必须的，仅仅是warning