Android missing layout_alignParentStart after upgrade

I upgraded from Android Studio 0.5 to 0.8 now I have heaps of issues, I resolved most of them but now I get this error

Error:(12) No resource identifier found for attribute ‘layout_alignParentStart’ in package ‘android’

I dont know why it does not have layout_alignParentStart anymore?!

am I missing something here?

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Answer

I had the same issue, my problem was the compileSdkVersion, I changed from 16 to 20 and it works.

I give you my build.gradle file:

apply plugin: 'com.android.application'

android {
    compileSdkVersion 20
    buildToolsVersion "19.1.0"

    defaultConfig {
        applicationId "mypackage"
        minSdkVersion 15
        targetSdkVersion 20
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:20.+'
    // You must install or update the Support Repository through the SDK manager to use this dependency.
    // You must install or update the Support Repository through the SDK manager to use this dependency.
    compile 'com.android.support:support-v4:20.+'
    // You must install or update the Support Repository through the SDK manager to use this dependency.
    compile 'com.android.support:support-v13:20.+'

}