Configuration 'androidTestCompile' is obsolete and has been replaced with 'androidTestImplementation' and 'androidTestApi'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html Configuration 'androidTestApi' is obsolete and has been replaced with 'androidTestImplementation'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html Configuration 'testCompile' is obsolete and has been replaced with 'testImplementation' and 'testApi'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html Configuration 'testApi' is obsolete and has been replaced with 'testImplementation'. It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

The Error in Andorid Studio.

Configuration 'androidTestCompile' is obsolete and has been replaced with 'androidTestImplementation' and 'androidTestApi'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

Configuration 'compile' is obsolete and has been replaced with 'implementation' and 'api'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

Configuration 'androidTestApi' is obsolete and has been replaced with 'androidTestImplementation'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

Configuration 'testCompile' is obsolete and has been replaced with 'testImplementation' and 'testApi'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

Configuration 'testApi' is obsolete and has been replaced with 'testImplementation'.
It will be removed at the end of 2018. For more information see: http://d.android.com/r/tools/update-dependency-configurations.html

->  Solution:-

Goto Gradle Scripts.

Then Goto build.gradle(Module: app)

As Shown in Image:-

And For Example if your dependencies looks Like this:

dependencies { compile fileTree(dir: 'libs', include: ['*.jar']) androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', { exclude group: 'com.android.support', module: 'support-annotations' }) compile 'com.android.support:appcompat-v7:25.0.1' compile 'com.android.support:design:25.0.1' compile 'com.android.support:support-v4:25.0.1' compile 'com.android.support:support-vector-drawable:25.0.1' testCompile 'junit:junit:4.12' }  You have to Just Change the following words: 1) compile to implementation where word compile is return. 2) testCompile to testImplementation where testCompile is return. 3) androidTestCompile to androidTestImplementation where androidTestCompile is return. -> See the solution for this Example.

dependencies {

    implementation fileTree(dir: 'libs', include: ['*.jar'])

    androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {

        exclude group: 'com.android.support', module: 'support-annotations'

    })

    implementation 'com.android.support:appcompat-v7:27.1.1'

    implementation 'com.android.support:design:27.1.1'

    implementation 'com.android.support:support-v4:27.1.1'

    implementation 'com.android.support:support-vector-drawable:27.1.1'

    testImplementation 'junit:junit:4.12'

}

If you Want to add third party library like retrofit and other library.Then you have to use implementation Keyword not compile Keyword.

For Example:

This is wrong.

compile 'com.squareup.retrofit2:retrofit:2.4.0'

This is Right.

implementation 'com.squareup.retrofit2:retrofit:2.4.0'

You Just have change to words as Shown in Error.