title: Entity Framework 6 - Entity classes get deleted when updating edmx, why is that? and what can I do to stop it?
body: <p>When updating the entity framework diagram using the EDMX Designer, sometimes the entities under the model.TT file get deleted and I then have to undo the changes in Source Control. </p>
  
  <p>What is the reason for this and what can I do to stop this from happening?</p>