Cannot resolve parameter MediatR.SingleInstanceFactory singleInstanceFactory about mediatr HOT 5 CLOSED

builder.RegisterSource(new ContravariantRegistrationSource());
builder.RegisterAssemblyTypes(typeof(IMediator).Assembly).AsSelf().AsImplementedInterfaces();
builder.Register<SingleInstanceFactory>(ctx =>
{
    var c = ctx.Resolve<IComponentContext>();
    return t => c.Resolve(t);
});
builder.Register<MultiInstanceFactory>(ctx =>
{
    var c = ctx.Resolve<IComponentContext>();
    return t => (IEnumerable<object>)c.Resolve(typeof(IEnumerable<>).MakeGenericType(t));
});

        builder.RegisterAssemblyTypes(assembly)
            .AsClosedTypesOf(typeof(IRequestHandler<,>))
            .AsImplementedInterfaces();

        builder.RegisterAssemblyTypes(assembly)
            .AsClosedTypesOf(typeof(IAsyncRequestHandler<,>))
            .AsImplementedInterfaces();

        builder.RegisterAssemblyTypes(assembly)
            .AsClosedTypesOf(typeof(INotificationHandler<>))
            .AsImplementedInterfaces();

        builder.RegisterAssemblyTypes(assembly)
            .AsClosedTypesOf(typeof(IAsyncNotificationHandler<>))
            .AsImplementedInterfaces();

 builder.RegisterAssemblyTypes(AppDomain.CurrentDomain.GetAssemblies())
               .Where(t => t.Name.EndsWith("Handler"))
               .AsImplementedInterfaces()
               .InstancePerRequest();

private static IElementGenerator<T> GetGenerator<T>(T model) where T : class
{
      var library = StructuremapMvc.ParentScope.CurrentNestedContainer.GetInstance<HtmlConventionLibrary>();
      return ElementGenerator<T>.For(library, t => StructuremapMvc.ParentScope.CurrentNestedContainer.GetInstance(t), model);
}