title: Conceptual side cannot be mapped to object side?
body: <p>I use the Entity Framework with Db-First approach. I used to have a table called Ranking that I mapped to an abstract base class with a few inherited concrete classes. Now I recently removed all the inheritance and choose to just use one concrete class called Ranking.</p>
  
  <p>But since I changed it back I get the following runtime Exception:</p>
  
  <p><em>Type 'DbModel.Ranking' in conceptual side  cannot be mapped to type 'My.Application.Models.Ranking' on the object side.  Both the types must be abstract or both must be concrete types.</em></p>
  
  <p>In my code generation I have set Abstract to false, but I don't know how to change this on the <em>conceptual</em> side.</p>
  
  <p>I even tried deleting the Ranking table from my table designer, and then update it again from the database. This didn't help either.</p>
  
  <p>Anyone an idea?</p>