解决问题：Android Studio Run时，APP安装失败--Installation failed with message Failed to establish session.

刚开始使用Android Studio, 使用的是红米Note 3 , MIUI 7.3 ，Run时，app安装不到手机上，提示：

Installation failed with message Failed to establish session.

It is possible that this issue is resolved by uninstalling an existing version of the apk if it is present, and then re-installing.

WARNING: Uninstalling will remove the application data!


Do you want to uninstall the existing application?

如图：

解决方法：

开发者选项界面中，最后一排有个- -“启用MIUI优化” ，默认是开启，把这个选项关掉，会提醒重启，重启后就好了

参考：http://blog.csdn.net/legend12300/article/details/69864547