title: ClassNotFoundException: org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider
body: <p>I try to start an Google appengine application in my eclipse.</p>
  
  <p>I have the Google plugin and I set the sdk for my application.</p>
  
  <p>But, when I start this one, I get the following error:</p>
  
  <pre><code>java.lang.ClassNotFoundException: org.datanucleus.store.appengine.jpa.DatastorePersistenceProvider
  </code></pre>
  
  <p>However, this class is present in the sdk which is present in my classpath.</p>
  
  <p>Why Appengine doesn't find this class ?</p>
  
  <p>Thanks.</p>