How to choose MobilenetV2 as backbone?

你好，我在配置文件中选择MobilenetV2时，出现了一些问题 。请问我该怎么解决呀？
![image](https://user-images.githubusercontent.com/47966300/75642167-86c1d380-5c75-11ea-88b5-8d9337a208f6.png)
错误信息：
![image](https://user-images.githubusercontent.com/47966300/75642212-afe26400-5c75-11ea-8f35-881d2490b42b.png)
![image](https://user-images.githubusercontent.com/47966300/75642226-b83a9f00-5c75-11ea-8e89-d8dc229e581a.png)

