“Default Activity Not Found” on Android Studio upgrade

Question

I upgraded IntelliJ Idea from 12.0.4 to 12.10.

Now all the modules in my Android project give the error:

Error: Default Activity Not Found

Answer 1

Exit Android Studio.

Go to path C:\Users\YOUR_WINDOW_USER_NAME\.AndroidStudio3.3\system

Remove /caches folder and /tmp folder