Any progress on this? I'm having the same issue developing a plugin for "Favorite Categories".
Unable to determine the principal end of an association between the types 'Nop.Core.Domain.Customers.RewardPointsHistory' and 'Nop.Core.Domain.Orders.Order'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.
modelBuilder.Conventions.Remove<PluralizingTableNameConvention>(); modelBuilder.Entity<Prenotazione>().Ignore(c => c.Ordine); //Where ordine and cliente are existing nop class (order and customer). modelBuilder.Entity<Prenotazione>().Ignore(c => c.Cliente);
and remove all foreignkey to existing nop table to solve all problems.
Is there any update on this? I am implementing a plugin in 2.7, and I am getting the same issue. I'll go ahead and look into the work around posted here.