Table missing from 'EF Designer from database' .edmx diagram

For anyone looking up this:

If you have a table formed of two Foreign Keys combined to form the Tables Primary Key and no other properties in the table the Entity Framework will not add this table to the Model although it exists in the background.

You do not need the intermediate Join table. The EF will add the Navigation property.

So in this case you would use something like: (User Object).Roles.add(new userrole object); save context changes to update;