Error in callback for watcher "options": "TypeError: Cannot read property 'level' of null TypeError

I got a dynamic cascader cascade selector, and found that an error was reported when switching data sources. I saw this article on the Internet to solve it perfectly. https://blog.csdn.net/weixin_43043994/article/details/100303097

The above article on how the problem occurs is very clear. The solution is to reload the component. Two methods, one with v-if, one with key

<template>
   <el-cascader
                 :options="dataForType"
                 :key="cascaderKey"
                 :props="props"
                 :show-all-levels="false"
                 filterable
                 v-model="dataRefValue"
                                  
    >
   </el-cascader>
</template>
 
<script>
   export default{
       data(){
          return {
                cascaderKey:1
            }
       },
       watch:{
            //切换数据源
             changeMenu(){
                ++this.cascaderKey
            }
       }
}
</script>