Didn't find class “com.google.firebase.provider.FirebaseInitProvider”

Question

Before, my program run well. But When I just updated my Android studio to the latest version (2.2 built on 15-sept-16), I am having the following error. When I built it, it says

Answer 1

I got the same error. I resolved it by :

1) Removing unnecessary packages in the build.gralde.

2) Disabling the Firebase plugin

3) Upgrading the build tool to the latest