Android studio java.lang.NoClassDefFoundError: android.support.v4.app.NavUtilsJB

I had this problem and just found the solution - answer is RTFM! Here are the instructions: https://developer.android.com/tools/building/multidex.html

Multidexing is a new feature and so requires a support library to be compatible with pre-lollipop devices. You need to add the following to your gradle file dependencies:

compile 'com.android.support:multidex:1.0.0'

Also enable multidex output in your gradle file:

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.0"

    defaultConfig {
        ...
        minSdkVersion 14
        targetSdkVersion 21
        ...

        // Enabling multidex support.
        multiDexEnabled true
    }
}

And then add the multidex support application to your manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.android.multidex.myapplication">
    <application
        ...
        android:name="android.support.multidex.MultiDexApplication">
        ...
    </application>
</manifest>

Note: If your app already extends the Application class, you can override the attachBaseContext() method and call MultiDex.install(this) to enable multidex. For more information, see the MultiDexApplication reference documentation.

@Override
protected void attachBaseContext(Context context) {
    super.attachBaseContext(context);
    MultiDex.install(this);
}

Again, see the instruction above for more information...

Hope this helps

Was stuck for hours due to this issue but finally got the solution.

Step#1:

dependencies {
compile 'com.android.support:multidex:1.0.0'
}

Step#2:

defaultConfig {
        multiDexEnabled true
    }

Step#3:

public class AppController extends Application {
    @Override
    public void onCreate() {
        super.onCreate();
        MultiDex.install(this);
    }
}

Happy coding!