Kotlin library 'rxkotlin-0.21.0.jar' has an unsupported format. Please update the library or the plugin

Question

The error in the title appears in Android Studio as a warning bar above all my code:

Android Studio version: 1.1.0
Kotlin plugin version for Android Studio: 0.11.91.AndroidStudio.4
build.gradle file that seems to be using all the most recent versions of the Kotlin libraries:

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'

android {
    compileSdkVersion 22
    buildToolsVersion "22.0.1"

    defaultConfig {
        applicationId "ca.amandeep.simpletransit"
        minSdkVersion 16
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.0.0'
    compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    compile 'com.squareup.retrofit:retrofit:1.9.0'
    compile('com.squareup.retrofit:converter-simplexml:1.9.0') {
        exclude module: 'stax'
        exclude module: 'stax-api'
        exclude module: 'xpp3'
    }
    compile 'com.squareup.okhttp:okhttp:2.3.0'
    compile 'com.squareup.okhttp:okhttp-urlconnection:2.3.0'
    compile 'com.google.guava:guava:18.0'
    compile 'com.facebook.stetho:stetho:1.0.1'
    compile 'com.facebook.stetho:stetho-okhttp:1.0.1'
    compile 'com.jakewharton.timber:timber:2.7.1'
    compile 'io.reactivex:rxkotlin:0.21.0'
    compile 'io.reactivex:rxandroid:0.24.0'
    compile 'com.github.techfreak:wizardpager:1.0.0'
}
buildscript {
    ext.kotlin_version = '0.11.91.1'
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
        classpath "org.jetbrains.kotlin:kotlin-android-extensions:$kotlin_version"
        classpath 'com.jakewharton.hugo:hugo-plugin:1.2.1'
    }
}
repositories {
    mavenCentral()
}

apply plugin: 'com.jakewharton.hugo'

Answer 1

I think they wrongly packaged this version. There is an issue about that on github :

https://github.com/ReactiveX/RxKotlin/issues/18

Maybe you should ping it.