title: Class diagrams created through objectaid in eclipse disappeared
body: <p>I am using eclipse plugin ObjectAid for creating class diagrams from my classes. After creating about 4 diagrams, the next day when I tried to open the class diagrams, I see that three out of the four diagrams are empty with an yellow exclamation icon near the ones which are empty.</p>
  
  <p>Any idea why this has happened? Is there any way to retrieve the class diagrams? </p>