co to znaczy?

System.MissingMethodException nie był obsługiwany przez kod użytkownika
HResult = -2146233069 Message = Metoda nie znaleziona: 'System.Data.Entity.ModelConfiguration.Configuration.PrimitivePropertyConfiguration System.Data.Entity.ModelConfiguration.Configuration.StructuralTypeConfiguration1.Property(System.Linq.Expressions.Expression12 <! 0, !! 0 >>) ”. Source = Att.Uds.DataLayerMappings StackTrace: at Att.Uds.DataLayerMappings.ItemTypeItemConfiguration..ctor () w Att.Uds.DataLayerMappings.UdsContext.OnModelCreating (DbModelBuilder modelBuilder) w c: TFS ATS-MSDev UDS Kod Att.Uds.DataLayerMappings UdsContext.cs: linia 163 w System.Data.Entity.DbContext.CallOnModelCreating (DbModelBuilder modelBuilder) w System.Data.Entity.Internal.LazyInternalContext.CreateModelBuilder () at System.Data.Entity.Internal .LazyInternalContext.CreateModel (LazyInternalContext internalContext) w System.Data.Entity.Internal.RetryLazy2.GetValue (wejście TInput) InnerException:

Błąd w tej klasie:

namespace Contoso.Fabrikam.DataLayerMappings
{ 
  public abstract class NamedEntityConfiguration<TEntity> : EntityBaseConfiguration<TEntity> where TEntity : NamedEntity
  {
    public ConfigurationColumn NameColumn;
    protected new int LastOrdinalPosition
    {
      get
      {
        return (NameColumn.Ordinal);
      }
    }
    public NamedEntityConfiguration() <=== EXCEPTION HERE
    {
      NameColumn = new ConfigurationColumn() { Ordinal = base.LastOrdinalPosition+1, Name = "Name", IsRequired = true, Length = 128 };
      this.Property(t => t.Name)
        .HasColumnName(NameColumn.Name)
        .HasColumnOrder(NameColumn.Ordinal)
        .HasMaxLength(NameColumn.Length);
      if(NameColumn.IsRequired)
      {
        this.Property(t => t.Name).IsRequired();
      }
    }
  }
}

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