Android Studio not recognizing classes after power failure

Question

A co-worker is having this problem for second time with Android Studio (first time he just got tired and reinstalled Windows)

After a power failure while using Android Studio on Windows 7, it couldn't resolve symbols for all android classes anymore. SDK and JDK seem well configured and we even downgraded to JDK 7u75 in order to discard that he originally installed JDK 8.

SDK Manager works and shows all needed APIs installed.

When creating a new project it comes with the same problem and reinstalling Android Studio doesn't help either. When exporting the project and testing it in another computer it works correctly.

What could it be?

Answer 1

Android Studio caches a lot of details that won't be fixed by simply running a clean/rebuild on your code.

When facing any issues like this the first thing to do is often go to File -> Invalidate Cache/Restart and perform a full cache drop and restart.