title: How to get rid off "An entity object cannot be referenced by multiple instances of IEntityChangeTracker"?
body: <p>I have a model in Ado.Net EF.
  I have a one to many relation and when I want to Add the entities I get the error</p>
  
  <p>"An entity object cannot be referenceed by multiple instances of IEntityChangeTracker"</p>
  
  <p>Any clue?</p>
  
  <p>Something similar to </p>
  
  <pre><code>Template template = new Template();
  ...
  ...
  while (from &lt; to)
  {
      Course course = new Course();
      .....
      template.Course.Add(course);
      .....
  }
  courseEntities.AddToTemplate(template); // Problem line
  courseEntities.SaveChanges();
  </code></pre>