Outdated Kotlin Runtime warning in Android Studio

In your (Project: [projectName]) build.gradle file find this: ext.kotlin_version = 'x.x.x' and replace x.x.x with the current version of your Kotlin plugin.

In order to check which is the current version of your Kotlin plugin:

1. Go to: Tools -> Kotlin -> Confugure Kotlin Plugin Updates

2. Click "Check again". After a second you will see the version of your Kotlin plugin. (If not up to date, your Kotlin plugin will be updated.)

N.B.: Also check your (Module: app) build.gradle file and assure that you do not use:

compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:1.2.21" 

but

compile 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.2.40'

Note the difference "...jre7..." -> "...jdk7...". Also replace "1.2.40" with your current Kotlin plugin version.

There are two pieces you may want to update:

1. kotlin runtime for the project
2. kotlin plugin

The answer by Ivo Stoyanov shows how to do this using the android studio menus. When I got the error message and tried this (updating the kotlin plugin) alone, it still complained about the kotlin runtime. You can update that on a project by project basis, by adding the line on ext.kotlin_version to the project build gradle, as some of the other answers indicate. But you'll need to know the kotlin runtime version for that. Alternatively, you can also do it through the menus, as I show here below, with the bonus that android studio shows you the available versions, and you can pick the most recent.

And then android studio will add in the appropriate line in your project build gradle.

the latest version of kotlin is 1.2.41 use this and syn your project.

buildscript {
ext.kotlin_version = '1.2.41'
repositories {
    google()
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.1.2'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}
}

As of March 8, 2019 the current kotlin version is '1.3.21'

Under build.gradle

buildscript {
   ext.kotlin_version = '1.3.21'
   repositories {
      google()
      jcenter()
   }
   dependencies {
      classpath 'com.android.tools.build:gradle:3.3.2'
      classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}

cheers

This issue comes when you update the kotlin plugin version popped up from android studio, but issue is current version of Android studio is not able to dynamically change the kotlin gradle plugin which is located in your project level Build.gradle file.

dependencies {
     classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.10"
}

How to solve this issue?

So you need to manually change this version, You can find that Here

I've run into this issue a few times in Android Studio and IDEA, found that if you go into your projects Gradle file and in your dependencies if you set the version of the kotlin-gradle-plugin to $kotlin_version then the warning message will tell you what version you need to set ext.kotlin_version to.

buildscript {
ext.kotlin_version = '1.2.40'
repositories {
    google()
    jcenter()
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.1.2'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}
}

buildscript {
    ext.kotlin_version = '1.2.50'
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.2'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

search for these two lines of code

ext.kotlin_version = '1.3.11'

classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

replace $kotlin_version with actual value (here it's 1.3.11)

classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.11"

after this your IDE will automatically suggest you the updated version

happy coding :)

Kotlin newest version:

buildscript {
    ext.kotlin_version = '1.2.41'

    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
        classpath 'com.google.gms:google-services:1.5.0-beta2'


        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

Bit annoying but studio acts like it some times. Below steps can fix the issue.

Go to

Settings -> Build, Execution, Development -> Gradle -> Use default gradle wrapper(recommended)

change this to Use local and back to Use default. Studio will ask about updating gradle after closing the settings windows.

I was facing same problem after updation my android studio from 3.0.1 to 3.2.1.My problem was solved after using this.

buildscript {
ext.kotlin_version = '1.2.51'
repositories {
    google()
    jcenter()
    mavenCentral()
    maven { url "https://jitpack.io" }
}
dependencies {
    classpath 'com.android.tools.build:gradle:3.2.1'
    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"

    // NOTE: Do not place your application dependencies here; they belong
    // in the individual module build.gradle files
}

}

I had faced this issue on latest Android Studio from Canary channel. You might want to consider downgrading Android Studio to stable version as well.

It happened for me on Android Studio 3.0 RC1.