title: JPA - "no Metadata found for type" exception
body: <p>The JPA implementation used in my application is Kodo.
  When attempting to query the DB for an entity, I get this very weird exception:</p>
  
  <p>org.apache.openjpa.persistence.ArgumentException: No metadata was found for type "class <strong>com.verid.ims.model.AddressUS</strong>". The class does not appear in the list of persistent types: [com.verid.ims.model.Birthdate, com.verid.ims.model.PersonName, <strong>com.verid.ims.model.AddressUS</strong>, com.rsa.idv.ims.feedback.IMSFeedback, com.rsa.idv.ims.notification.IMSNotification, com.rsa.idv.ims.provider.IMSProvider, com.rsa.idv.ims.notification.NotificationEntry, com.rsa.idv.ims.enroll.SecretUserQuestion, com.rsa.idv.ims.enroll.Enrollment].</p>
  
  <p>Please take into account that the AddressUS class, which according to the exception does not appear in the list of persistent types, is actually in the list! (Bold)</p>
  
  <p>The AddressUS class is mapped in my orm.xml file (it's not in the persistence.xml descriptor since it's not an entity, only an embeddable). Here is the mapping:</p>
  
  <pre><code>&lt;embeddable class="com.verid.ims.model.AddressUS"&gt;
    &lt;attributes&gt;
      &lt;basic name="city" /&gt;
      &lt;basic name="state"&gt;
        &lt;enumerated&gt;STRING&lt;/enumerated&gt;
      &lt;/basic&gt;
     &lt;basic name="street1" /&gt;
     &lt;basic name="street2" /&gt;
     &lt;basic name="zipcode" /&gt;
     &lt;basic name="suite" /&gt;
    &lt;/attributes&gt;
  &lt;/embeddable&gt;
  </code></pre>
  
  <p>Needless to say, the persistence.xml descriptor refers to the orm.xml file.</p>
  
  <p>The exception only happens on some environments (not all of them), which basically means that it's an environmental problem. What could cause this?</p>