[InvalidOperationException: Failed to Get because of circular references]
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.ValidateCircularReference(ContentReference contentLink, HashSet`1 visitedContents)
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.GetSetting(ContentReference contentLink, HashSet`1 visitedContents)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.GetSetting(ContentReference contentLink, HashSet`1 visitedContents)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.GetSetting(ContentReference contentLink, HashSet`1 visitedContents)
   at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.Get(ContentReference contentLink)
   at EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler.Get(ContentReference contentLink, String languageBranch)
   at EPiServer.Core.Internal.LanguagePipeline.Pipe(ContentReference contentLink, IContent contentInstance, LoaderOptions loaderOptions, Func`3 loadingDelegate)
   at EPiServer.Core.Internal.ProviderPipelineImplementation.GetItem(ContentProvider provider, ContentReference contentLink, LoaderOptions loaderOptions)
   at EPiServer.Core.Internal.DefaultContentLoader.TryGet[T](ContentReference contentLink, LoaderOptions loaderOptions, T& content)
   at EPiServer.Core.Html.StringParsing.ContentFragment.GetContent(Boolean enableMasterLanguageFallback)
   at EPiServer.Core.Html.StringParsing.ContentFragment.GetSecurityDescriptor()
   at EPiServer.Core.ContentAreaItem..ctor(ContentFragment fragment)
   at EPiServer.Core.ContentArea.<>c.b__19_0(ContentFragment fragment)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Collections.ObjectModel.ObservableCollection`1.CopyFrom(IEnumerable`1 collection)
   at EPiServer.Core.ContentArea.get_Items()
   at EPiServer.Cms.Shell.Json.Internal.ContentAreaConverter.WriteJson(JsonWriter writer, Object value, JsonSerializer serializer)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeConvertable(JsonWriter writer, JsonConverter converter, Object value, JsonContract contract, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeDictionary(JsonWriter writer, IDictionary values, JsonDictionaryContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.SerializeObject(JsonWriter writer, Object value, JsonObjectContract contract, JsonProperty member, JsonContainerContract collectionContract, JsonProperty containerProperty)
   at Newtonsoft.Json.Serialization.JsonSerializerInternalWriter.Serialize(JsonWriter jsonWriter, Object value, Type objectType)
   at Newtonsoft.Json.JsonSerializer.SerializeInternal(JsonWriter jsonWriter, Object value, Type objectType)
   at EPiServer.Shell.Services.Rest.RestResult.ExecuteResult(ControllerContext context)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.b__1e(IAsyncResult asyncResult)
   at EPiServer.Shell.Services.Rest.RestControllerBase.EndExecute(IAsyncResult asyncResult)
   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

So I used DotPeak to see what this DefaultLanguageSettingsHandler is doing but I can't get my head araound it. 


What I can see from DotPeak is that this ValidateCircularReference throws this InvalidOperationException when "visitedContents" contains the same page 

    private void ValidateCircularReference(ContentReference contentLink, HashSet visitedContents)
    {
      if (visitedContents != null && visitedContents.Contains(contentLink))
      {
        DefaultContentLanguageSettingsHandler.log.Warn((object) string.Format("Failed to Get because there are circular references for contents : '{0}'", (object) string.Join(",", visitedContents.Select((Func) (c => c.ToString())))));
        throw new InvalidOperationException("Failed to Get because of circular references");
      }
    }

If I check the log I can see this 
2016-11-18 10:49:05,285 [159] WARN EPiServer.Core.Internal.DefaultContentLanguageSettingsHandler: Failed to Get because there are circular references for contents : '84,5,1,4'

so I ran a sql query and got this
pkId fkParentID ContentPath Content typ
1    NULL       .           SysRoot
4    1          .1.         SysContentFolder
5    1          .1.         UtvecklingStartPage
84   4          .1.4.       SysContentAssetFolder

Now the page I'm on is that with pkId 5 and this page has one property, a Content area, that for the moment is empty. So I have no clue why I get this circular exception.

based on al this information I have three questions

1. What is DefaultLanguageSettingsHandler responsible of?
2. Why and when can this error occur? (I mean, how can the start page reference it self when there is no content on it?)
3. How do I make this error dissapear?

Thanks.