“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

In my case I refactored a member variable that was named "activity", I renamed it to "context"... I found out that the refactor was made to the activity tags in manifest, and I found them context tags instead... this is really stupid from Android Studio!