After the Android Studio 2.0 update while the gradle build finishes I get this :
Session \'app\': Error Launching activity .
It prevents the app from starting
OK already so many possible solutions for this problem, if none of those works then try this.
I faced this problem when I first uninstalled my app then tried reinstalling from ADB. But then after trying these many solutions, I realized that uninstalling app nowadays does not really uninstall it. It just disables it for few days so that it can be enabled in case you change your mind.
Now I am not sure whether its done by LG or Native Android Nougat.
I just went in Settings-> apps-> my-app and uninstalled it completely. After that from Android studio I am able to install the app again properly without this error.