Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.appcompat.R$styleable" on path: DexPathList

Question

I am getting the following error on Intellij 15.0

Caused by: java.lang.ClassNotFoundException: Didn't find class "android.support.v7.appcompat.R$styleable" on path: DexPathList

I have defined the Design & AppCompat libraries but i am not sure what's going wrong? The following is my Activity:

  import android.app.Activity;
    import android.os.Bundle;
    import android.support.design.widget.NavigationView;
    import android.support.design.widget.Snackbar;
    import android.support.v4.app.FragmentManager;
    import android.support.v4.widget.DrawerLayout;
    import android.support.v7.app.ActionBarDrawerToggle;
    import android.support.v7.app.AppCompatActivity;
    import android.support.v7.widget.Toolbar;

    public class DashboardActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private NavigationView navigationView;
    private DrawerLayout drawerLayout;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.dashboard);

    }
    }

My layout is:

I am not using gradle, i have also attached screen shots of my Project Structure