Session 'app': Error Launching activity

Question

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

Answer 1

Try reinstalling the app, this solved the error for me. The trick was that, I uninstalled my app, but Android didn't truly uninstall it. On my phone, there is a guest user (my sister uses it sometimes). If you uninstall the app from your main user, it will still be available on the phone, but only for the guest user. It looks like Android Studio can't handle this case. I guess it detects that the app is installed, so it will not be reinstalled again for the current user, hence the OS can't access and launch the activity. Nice bug, I'll report it.