Autofac.Core.DependencyResolutionException: A delegate registered to create instances of 'System.Web.HttpSessionStateBase' returned null.
   at Autofac.Core.Activators.Delegate.DelegateActivator.ActivateInstance(IComponentContext context, IEnumerable`1 parameters)
   at Autofac.Core.Resolving.ComponentActivation.Activate(IEnumerable`1 parameters)
   at Autofac.Core.Lifetime.LifetimeScope.GetOrCreateAndShare(Guid id, Func`1 creator)
   at Autofac.Core.Resolving.ComponentActivation.Execute(IEnumerable`1 parameters)
   at Autofac.Core.Resolving.ResolveOperation.Resolve(ISharingLifetimeScope activationScope, IComponentRegistration registration, IEnumerable`1 parameters)
   at Autofac.Core.Lifetime.LifetimeScope.ResolveComponent(IComponentRegistration registration, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.TryResolveService(IComponentContext context, Service service, IEnumerable`1 parameters, Object& instance)
   at Autofac.ResolutionExtensions.ResolveService(IComponentContext context, Service service, IEnumerable`1 parameters)
   at Autofac.ResolutionExtensions.Resolve(IComponentContext context, Type serviceType)
   at YAF.Core.AutoFacServiceLocatorProvider.Get(Type serviceType)
   at YAF.Types.Interfaces.IServiceLocatorExtensions.Get[TService](IServiceLocator serviceLocator)
   at YAF.Types.Interfaces.IServiceLocatorExtensions.Get[TService](IHaveServiceLocator haveLocator)
   at YAF.Core.UserPageBase.InitUserAndPage()