Gradle failed to sync with 'unable to find optional library'

Question

I had to reinstall my system and today I get this error in Android Studio when I try to sync with gradle:

Warning: Unable to find optional library: org.apach         


        

Answer 1

Top level build.gradle - /build.gradle

buildscript {
...
dependencies {
    classpath 'com.android.tools.build:gradle:1.3.1'
}
}

Module specific build.gradle - /app/build.gradle

android {
compileSdkVersion 23
buildToolsVersion "23.0.0"
useLibrary 'org.apache.http.legacy'
...
}

Add org.apache.http.legacy.jar which is in Android/Sdk/platforms/android-23/optional folder to app/libs directory and sync your project