I spent 5 days trying to solve this simple error. If you try to add Firebase to your project through Android Studio Firebase menu , you may have this problem. DESCRIPTION: Firebase is connected and so firebase:firebase-core:XX.X.X works, but then you wanto add a realtime database or the authentication package and the you find the next error: Failed to resolve: firebase-database-15.0.0 I don't know why Firebase adds old versions to your project instead of the latest stable version, but here's the solution . Just change your implementation 'com.google.firebase:firebase-core:16.0.3' implementation 'com.google.firebase:firebase-auth:16.0.1' implementation 'com.google.firebase:firebase-database:16.0.1:15.0.0' to the last version of each Firebase package ( here ) which, at the moment of writing this post, were the following: implementation 'com.google.firebase:firebase-core:16.0.4' implementation 'com.google.firebase:firebase-auth...
Blog personal de Daniel Vento