Error in render: "typeerror: cannot read properties of undefined (reading 'length')" --- error when calling interface

Question why

The level is too deep

<view class="input head-img">
      <text> Head portrait </text>
      <image :src="person.headerImg" />
    </view>

	messageRequest() {
    
				message().then(res => {
    
					console.log(res.data);
					// （ Step on the pit ）Error in render: “TypeError: Cannot read properties of undefined (reading ‘length‘)“
					// If the level is too deep, an error will be reported -- Pay attention to template The layer should not be too deep --- You can define multiple layers here 
					this.person = res.data.userInfo;
					console.log(this.person);
				});
			}

resolvent
// （ Step on the pit ）Error in render: “TypeError: Cannot read properties of undefined (reading ‘length‘)“
// If the level is too deep, an error will be reported – Pay attention to template The layer should not be too deep —
You can define multiple layers here