title: NoClassDefFoundError at Google Play Services V2 library
body: <p>I get the following exception when trying to use the Google Play Services V2 library after following the <a href="https://developers.google.com/maps/documentation/android/start" rel="noreferrer">official tutorial</a>.</p>
  
  <pre><code>java.lang.NoClassDefFoundError: com.google.android.gms.R$string
  at com.google.android.gms.common.GooglePlayServicesUtil.b(Unknown Source)
  at com.google.android.gms.common.GooglePlayServicesUtil.a(Unknown Source)
  at com.google.android.gms.common.GooglePlayServicesUtil.getErrorDialog(Unknown Source)
  </code></pre>
  
  <p>Where did I go wrong?</p>