title: EF6 Code first "model backing DataContext has changed" error (.mdf Db)
body: <p>I'm new to the code first methodology.</p>
  
  <p>I'm getting this error:</p>
  
  <p>"The model backing the 'DataContext' context has changed since the database was created. Consider using Code First Migrations to update the database".</p>
  
  <p>I have a WPF app using EF6 &amp; MVVM running against a local db (.mdf life).</p>
  
  <p>I created a new model, called langauges then I added a new DbSet&lt; langauges > collection to my datacontext.</p>
  
  <p>When the code tries to instantiate the a datacontext object, I get the error above.</p>
  
  <p>What am I missing? For all my other new tables/models I could just create them in code, run a test method to create a record in the new table/model and then EF code first would automatically create the new table and add the entry with complaining. Why won't it work now?</p>