In project 'app' a resolved Google Play services library dependency depends on another at an exact version

Trying to create a simple app with FireStore and Google Authentication. Having problem with the gradle:

In project 'app' a resolved Google Play services library dependency depends on another at an exact version (e.g. "[15.0. 1]", but isn't being resolved to that version. Behavior exhibited by the library will be unknown.

Dependency failing: com.google.android.gms:play-services-flags:15.0.1 -> com.google.android.gms:play-services-basement@[ 15.0.1], but play-services-basement version was 16.0.1.

The following dependencies are project dependencies that are direct or have transitive dependencies that lead to the art ifact with the issue. -- Project 'app' depends onto com.google.firebase:[email protected] -- Project 'app' depends onto com.firebaseui:[email protected]

For extended debugging info execute Gradle from the command line with ./gradlew --info :app:assembleDebug to see the dep endency paths to the artifact. This error message came from the google-services Gradle plugin, report issues at https:// github.com/google/play-services-plugins and disable by adding "googleServices { disableVersionCheck = false }" to your b uild.gradle file.

    apply plugin: 'com.android.application'

    android {
        compileSdkVersion 27
        defaultConfig {
            applicationId "myapp.com"
            minSdkVersion 19
            targetSdkVersion 27
            versionCode 11
            versionName "1.1"
            testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
            multiDexEnabled true
        }
        buildTypes {
            release {
                minifyEnabled false
                proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            }
        }
    }

    dependencies {
        implementation fileTree(dir: 'libs', include: ['*.jar'])
        implementation 'com.android.support:appcompat-v7:27.1.1'
        implementation 'com.android.support.constraint:constraint-layout:1.1.3'
        testImplementation 'junit:junit:4.12'
        androidTestImplementation 'com.android.support.test:runner:1.0.2'
        androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
        implementation 'com.google.firebase:firebase-firestore:17.1.5'

        implementation 'com.firebaseui:firebase-ui-auth:4.2.0'

    }

    apply plugin: 'com.google.gms.google-services'
    com.google.gms.googleservices.GoogleServicesPlugin

Project gradle:

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'

        classpath 'com.google.gms:google-services:4.2.0'

    }
}

Can somebody help me?

There are many answers here for individual solutions that do not really get down to the problem. Here is how to solve this in general:

As the original log output suggests, it is useful to run the build in the terminal with the following command:

./gradlew --info assembleDebug

This will give you a list of all dependencies that are involved in the conflict. It looks similar to this (I removed the package name stuff to make it a bit more readable):

Dependency Resolution Help: Displaying all currently known paths to any version of the dependency: Artifact(groupId=com.google.firebase, artifactId=firebase-iid)

-- task/module dep -> [email protected]
---- firebase-analytics:17.2.0 library depends -> [email protected]
------ play-services-measurement-api:17.2.0 library depends -> [email protected]

-- task/module dep -> [email protected]
---- firebase-core:17.2.0 library depends -> [email protected]
------ firebase-analytics:17.2.0 library depends -> [email protected]
-------- play-services-measurement-api:17.2.0 library depends -> [email protected]

-- task/module dep -> [email protected]
---- play-services-measurement-api:17.2.0 library depends -> [email protected]

-- task/module dep -> [email protected]

-- task/module dep -> [email protected]
---- firebase-messaging:17.1.0 library depends -> firebase-iid@[16.2.0]

-- task/module dep -> com.pressenger:[email protected]
---- com.pressenger:sdk:4.8.0 library depends -> [email protected]
------ firebase-messaging:17.1.0 library depends -> firebase-iid@[16.2.0]

From this list you get to know 2 things:

1. Where is the conflicting depedency found
2. What versions of the conflicting dependency are set up

In my case the conflicting dependency is firebase-iid: It's either @19.0.0 or @16.2.0

To fix this you must define the top-level dependency of the wrong firebase-iid explicitly in your build.gralde.

So in the upper log you can see that there are 2 examples of an out-dated version of [email protected]. One comes from -- task/module dep -> [email protected] the other one from a third-party library (pressenger). We don't have influence on the third-party library, so nothing to do here. But for the other dependency, we have to declare it explicitly with the correct version:

implementation 'com.google.firebase:firebase-messaging:20.0.0'

Now the build works again. Happy ending :)

There's a known bug with Google Services 4.2.0 that may cause this. Downgrading your google-services version to 4.1.0 in your project's build.gradle may resolve the issue

buildscript {
    dependencies {
        classpath 'com.google.gms:google-services:4.1.0' //decreased from 4.2.0
    }
}

The problem was it was missing a dependency. Adding com.google.firebase:firebase-auth solved the issue.

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.firebase:firebase-firestore:17.1.5'

//    implementation'com.google.firebase:firebase-core:16.0.6'
//    implementation'com.google.firebase:firebase-storage:16.0.5'

    implementation'com.google.firebase:firebase-auth:16.1.0' => add this line
    implementation 'com.firebaseui:firebase-ui-auth:4.2.0'
}

There was a bug related to google-services that was eventually fixed in version 4.3.3.

So you can either use 4.3.3 or the latest version (check here)

classpath 'com.google.gms:google-services:4.3.3' // or latest version

or downgrade to 4.1.0

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