title: Entity Framework Core DbContextOptionsBuilder.UseModel creates EntityTypes that have no properties
body: <p>I am working on a .NET Core project using entity framework core (2.0.1). </p>
  
  <p>I have a plugin architecture requiring different models to be loaded based on the plugins attached, so trying to dynamically load the models when adding the dbcontext to the DI container using the DbContextOptionsBuilder.UseModel method. </p>
  
  <p>Regardless on if I define a new Model or a ModelBuilder, the EntityTypes I am adding do not appear to be doing so correctly and once added to the dbcontext do not appear to have any properties. </p>
  
  <p>I am not sure if there is a convention I need to be adding for this to work, or what I may be missing. Any help would be appreciated.</p>
  
  <pre><code>_services.AddDbContext&lt;DataContext&gt;(options =&gt;
          {
              switch (_config.DatabaseType.ToLower())
              {
                  case "postgres":
                      options.UseNpgsql(_config.ConnectionString);
                      break;
                  case "sqlserver":
                      options.UseSqlServer(_config.ConnectionString);
                      break;
              }
  
              var convention = new Microsoft.EntityFrameworkCore.Metadata.Conventions.ConventionSet();
              var mb = new ModelBuilder(convention);
              foreach (var definition in definitionList)
              {
                  mb.Entity(definition.Type);
              }
              options.UseModel(mb.Model);
          });
  </code></pre>
  
  <p>Resolves into:</p>
  
  <p><a href="https://i.stack.imgur.com/TsRO6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/TsRO6.png" alt="enter image description here"></a></p>
  
  <p>Correctly creates the 5 EntityTypes, but then once I expand one of the Entity Types it has no properties. </p>
  
  <p><a href="https://i.stack.imgur.com/XDHnC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XDHnC.png" alt="enter image description here"></a></p>
  
  <p>If I do the same using the standard convention of adding the EntityType via the override of the dbcontext onmodelbuilding, the properties are all there correctly...</p>