Android : Cannot creating signed APK after enabling Proguard
<p>I just enable <strong>proguard</strong> in my project . After that i run the apk successfully by using <strong>debug apk</strong>.</p>

<p>When I try to creating a <strong>signed Apk</strong> am getting an error </p>

<pre><code>Error:Execution failed for task ':app:proguardRelease'.
 &gt; java.io.IOException: Please correct the above warnings first.
</code></pre>

<p><strong>My Gradle file like this</strong></p>

<pre><code>apply plugin: 'com.android.application'

android {
compileSdkVersion 22
buildToolsVersion "22.0.1"

defaultConfig {
    applicationId "com.android4dev.navigationview"
    minSdkVersion 15
    targetSdkVersion 22
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.android.support:recyclerview-v7:22.1.1'
compile 'com.android.support:appcompat-v7:22.2.0'
compile 'com.android.support:design:22.2.0'
compile 'de.hdodenhof:circleimageview:1.3.0'
compile 'com.github.traex.rippleeffect:library:1.3'
compile 'com.loopj.android:android-async-http:1.4.9'
compile 'com.google.android.gms:play-services:8.1.0'

}
</code></pre>

<p><strong>Warning</strong></p>

<pre><code>Warning:com.google.android.gms.internal.zzhu: can't find referenced class android.security.NetworkSecurityPolicy
Warning:there were 3 unresolved references to classes or interfaces.
     You may need to add missing library jars or update their versions.
     If your code works fine without the missing classes, you can suppress
     the warnings with '-dontwarn' options.
     (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)
 :app:proguardRelease FAILED
  Error:Execution failed for task ':app:proguardRelease'.
  &gt; java.io.IOException: Please correct the above warnings first.
</code></pre>

<p>I tried <code>-dontwarn org.apache.lang.**</code>, but still am getting the same issue</p>

<p>Can any please help me to recover this problem.</p>