Uncaught TypeError: Right-hand side of 'instanceof' is not an object

1、错误描述

log.js?1afd:24 [HMR] Waiting for update signal from WDS...
vue.runtime.esm.js?2b0e:3261 
Uncaught TypeError: Right-hand side of 'instanceof' is not an object
at assertType (vue.runtime.esm.js?2b0e:1703) 
at assertProp (vue.runtime.esm.js?2b0e:1662)
at validateProp (vue.runtime.esm.js?2b0e:1596)  
at loop (vue.runtime.esm.js?2b0e:3442) 
at initProps (vue.runtime.esm.js?2b0e:3475)
at initState (vue.runtime.esm.js?2b0e:3416) 
at VueComponent.Vue._init (vue.runtime.esm.js?2b0e:4720)
at new VueComponent (vue.runtime.esm.js?2b0e:4888)
at createComponentInstanceForVnode (vue.runtime.esm.js?2b0e:4391) 
at init (vue.runtime.esm.js?2b0e:4222)

2、错误原因

       message后面应该是一个数据类型，如String、Number

<template>
	<div></div>
</template>

<script>
	export default{
		name: 'You',
		props: {
			message: '欢迎光临！'
		}
	}
</script>

<style>
</style>

3、解决办法

      由于message是个字符串类型，需要写成message:String

<template>
	<div>{{message}}</div>
</template>

<script>
	export default{
		name: 'You',
		props: {
			message: String
		}
	}
</script>

<style>
</style>