R.java not found on Android Studio 3.2

Question

We\'ve got a strange behaviour in an Android project we inherited. The APK builds without error but the IDE keeps complaining about missing R class<

Answer 1

In my case, I have to revert the version of android build tool:

classpath 'com.android.tools.build:gradle:3.2.1' // use this version instead of 3.3.0

Answer 2

First, thanks for all your support !

After reading @Kingfisher Phuoc response, I finally found that it was an incompatibility between my Android Studio 3.2 and using Android gradle plugin 3.3.

I updated my Android Studio to match the plugin and now it is working !

It looks like the way the R class is generated have been updated in the 3.3 version (source: release notes, look for "Faster R class generation for library projects")

Answer 3

In my case R.java always generates in build\generated\not_namespaced_r_class_sources . You can try cleaning and rebuilding the product.