After migrating from Android Studio 3.0 (Canary 5) to Android Studio 3.0 (Beta 1), and moving to latest gradle , i.e. \'com.android.tools.build:gradle:3.0.0-beta1\'
\'com.android.tools.build:gradle:3.0.0-beta1\'
First you need to clean the project , and then rebuild it.
Build ----> Clean Project
Build ----> Rebuild Project