title: Value cannot be null. Parameter name: source
body: <p>This is probably the biggest waste of time problem I have spent hours on solving for a long time.</p>
  
  <pre><code>var db = new hublisherEntities();
  establishment_brands est = new establishment_brands();
  
  est.brand_id = 1;
  est.establishment_id = 1;
  est.price = collection["price"];
  est.size = collection["size"];
  
  db.establishment_brands.Add(est);
  db.SaveChanges();
  </code></pre>
  
  <p>This gives me an error of</p>
  
  <blockquote>
    <p>Value cannot be null. Parameter name: source</p>
  </blockquote>
  
  <p>stacktrace of</p>
  
  <blockquote>
    <p>[ArgumentNullException: Value cannot be null. Parameter name: source] 
    System.Linq.Enumerable.Any(IEnumerable<code>1 source, Func</code>2 predicate)
    +4083335    System.Data.Entity.Internal.InternalContext.WrapUpdateException(UpdateException
    updateException) +87<br>
    System.Data.Entity.Internal.InternalContext.SaveChanges() +193<br>
    System.Data.Entity.Internal.LazyInternalContext.SaveChanges() +33<br>
    System.Data.Entity.DbContext.SaveChanges() +20 ... ...</p>
  </blockquote>
  
  <p>I just want to add an entity to the table. The ORM is EF.</p>