Yesterday,my app was working fine.
Today, I don\'t know why, the app didn\'t compile anymore after I reopened the Android Studio.
The error shown is
I faced the same problem today. Google comes with the new release on 02 May 2018.
Please go to the link and set the version no according to the doc:
https://firebase.google.com/support/release-notes/android#20180502
for e.g.
Firebase Core com.google.firebase:firebase-core:15.0.2