Getting error when I use same version dependencies in gradle

Question

I'm confused on why this isn't working because my previous versions worked but they were a lower version:

implementation 'com.google.firebase:firebase-database:12.0.1'
implementation 'com.google.firebase:firebase-storage:12.0.1'
compile 'com.google.android.gms:play-services-auth:12.0.1'
implementation 'com.google.firebase:firebase-auth:12.0.1'

However, when I tried to upgrade to a newer version I get the error in this image:

And it says that I am mixing versions but I'm not, since I put them all the same.

All gms/firebase libraries must use the exact same version specification (mixing versions can lead to runtime crashes). Found versions 15.1.0, 15.0.2, 15.0.1, 15.0.0. Examples include `com.google.firebase:firebase-iid:15.1.0` and `com.google.android.gms:play-services-measurement-base:15.0.2`

Answer 1

Starting from May 2018:

Firebase Android SDKs now have independent version numbers, allowing for more frequent, flexible updates.

According to this , please change the following lines of code:

implementation 'com.google.firebase:firebase-database:12.0.1'
implementation 'com.google.firebase:firebase-storage:12.0.1'
implementation 'com.google.firebase:firebase-auth:12.0.1'

to

implementation 'com.google.firebase:firebase-database:16.0.2'
implementation 'com.google.firebase:firebase-storage:16.0.2'
implementation 'com.google.firebase:firebase-auth:16.0.3'

And according to this , please change the following line of code:

compile 'com.google.android.gms:play-services-auth:12.0.1'

to

implementation 'com.google.android.gms:play-services-auth:16.0.0'

And according to this , please change the following line of code:

implementation 'com.firebaseui:firebase-ui-auth:3.1.0'

to

implementation 'com.firebaseui:firebase-ui-auth:4.1.0'

Please also add the following dependecy, which is now mandatory:

implementation 'com.google.firebase:firebase-core:16.0.3'

Also be sure to use also the latest version for Google play services in your top level build.gradle file:

classpath 'com.google.gms:google-services:4.1.0'

Answer 2

change dependency in Project gradle

dependencies {
    classpath 'com.android.tools.build:gradle:3.1.4'


    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
    classpath 'com.google.gms:google-services:4.0.1'
}

and in module

implementation 'com.google.firebase:firebase-core:16.0.3'
implementation 'com.google.firebase:firebase-database:16.0.2'
implementation 'com.google.firebase:firebase-auth:16.0.3'
implementation 'com.google.firebase:firebase-storage:16.0.2'
implementation 'com.firebaseui:firebase-ui-database:4.1.0'
implementation 'com.firebaseui:firebase-ui-auth:4.1.0'
implementation 'com.google.firebase:firebase-ads:15.0.1'
implementation 'com.google.firebase:firebase-config:16.0.0'