I updated Android Studio to version 2.0. The build failed and also takes longer than Android Studio version 1.5 to build. Every time I run my application, I clean and reload
Probably you are shrinking the resources while avoiding minifying:
minifyEnabled false
shrinkResources true
If you want to shrink the resources, you have to enable minifying:
minifyEnabled true
shrinkResources true
Older versions of Build Tools were ignoring this issue, but it started throwing compilation issues on Build Tools 2.2.3
More information here: https://developer.android.com/studio/build/shrink-code.html#shrink-resources