I've noticed that others are getting the same problem. I have not been able to determine the cause of the problem and I have not been able to actually solve the problem, only temporarily make it go away by various means mentioned in other posts. (Recycling app-pool, throwing out indices...) It always reoccur though.

One poster was asked about load balancing. The site where I have the problem is load balanced with synced folders. Could this be the cause of the problem?

I'm submitting a dump from the windows log, hoping it might help.

Application information: 

    Application domain: /LM/W3SVC/27/ROOT-1-130397762940904712 

    Trust level: Full 

    Application Virtual Path: / 

    Application Path: d:\inetpub_synced\*******\ 

    Machine name: ******* 

 

Process information: 

    Process ID: 3484 

    Process name: w3wp.exe 

    Account name: IIS APPPOOL\*******

 

Exception information: 

    Exception type: NullReferenceException 

    Exception message: Object reference not set to an instance of an object.

   at Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.b__2(UmbracoContext context, Boolean preview)

   at Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.GetById(UmbracoContext umbracoContext, Boolean preview, Int32 nodeId)

   at Umbraco.Web.PublishedCache.ContextualPublishedCache`1.GetById(Boolean preview, Int32 contentId)

   at Umbraco.Web.UmbracoHelper.TypedDocumentById(Int32 id, ContextualPublishedCache cache)

   at uHelpsy.Helpers.IPublishedContentHelper.GetNode(Int32 nodeId) in D:\_PROJECTS\Personal\uHelpsy - Library\uHelpsy\Source\uHelpsy.Web\Helpers\IPublishedContentHelper.cs:line 24

   at uHelpsy.Extensions.CollectionExtensions.b__6(SearchResult x) in D:\_PROJECTS\Personal\uHelpsy - Library\uHelpsy\Source\uHelpsy.Web\Extensions\CollectionExtensions.cs:line 54

   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()

   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()

   at ASP._Page_Views_Partials_uBlogsy_Landing_uBlogsyLandingListPosts_cshtml.<>c__DisplayClass2.b__1(TextWriter __razor_helper_writer) in d:\inetpub_synced\*******\Views\Partials\uBlogsy\Landing\uBlogsyLandingListPosts.cshtml:line 67

   at ASP._Page_Views_Partials_uBlogsy_Landing_uBlogsyLandingListPosts_cshtml.Execute() in d:\inetpub_synced\*******\Views\Partials\uBlogsy\Landing\uBlogsyLandingListPosts.cshtml:line 52

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()

   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)

   at StackExchange.Profiling.MVCHelpers.WrappedView.Render(ViewContext viewContext, TextWriter writer)

   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, CacheDependency cacheDependency, Nullable`1 timeout, Func`1 getCacheItem, Object syncLock)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, CacheDependency cacheDependency, Nullable`1 timeout, Func`1 getCacheItem)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, Nullable`1 timeout, Func`1 getCacheItem)

   at Umbraco.Web.CacheHelperExtensions.CachedPartialView(CacheHelper cacheHelper, HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, String cacheKey, ViewDataDictionary viewData)

   at Umbraco.Web.HtmlHelperRenderExtensions.CachedPartial(HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, Boolean cacheByPage, Boolean cacheByMember, ViewDataDictionary viewData)

   at ASP._Page_Views_uBlogsyLanding_cshtml.b__2() in d:\inetpub_synced\*******\Views\uBlogsyLanding.cshtml:line 23

   at System.Web.WebPages.WebPageBase.<>c__DisplayClassb.b__9(TextWriter tw)

   at ASP._Page_Views__uBlogsyBaseBlog_cshtml.b__7() in d:\inetpub_synced\*******\Views\_uBlogsyBaseBlog.cshtml:line 35

   at System.Web.WebPages.WebPageBase.<>c__DisplayClassb.b__9(TextWriter tw)

   at ASP._Page_Views__uBlogsyBaseSite_cshtml.Execute() in d:\inetpub_synced\*******\Views\_uBlogsyBaseSite.cshtml:line 44

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()

   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)

   at System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body)

   at System.Web.WebPages.WebPageBase.PopContext()

   at System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body)

   at System.Web.WebPages.WebPageBase.PopContext()

   at StackExchange.Profiling.MVCHelpers.WrappedView.Render(ViewContext viewContext, TextWriter writer)

   at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)

   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.b__17()

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)

   at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)

   at System.Web.Mvc.Controller.<>c__DisplayClass1d.b__19()

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.b__0()

   at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.b__3(IAsyncResult ar)

   at System.Web.Mvc.MvcHandler.<>c__DisplayClass8.b__3(IAsyncResult asyncResult)

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.b__3(IAsyncResult ar)

   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

 

Request information: 

    Request URL: http://*******/blogg 

    Request path: /blogg 

    User host address: ******* 

    User:  

    Is authenticated: False 

    Authentication Type:  

    Thread account name: IIS APPPOOL\*******

 

Thread information: 

    Thread ID: 10 

    Thread account name: IIS APPPOOL\***********

    Is impersonating: False 

 

    Stack trace:    at Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.b__2(UmbracoContext context, Boolean preview)

   at Umbraco.Web.PublishedCache.XmlPublishedCache.PublishedContentCache.GetById(UmbracoContext umbracoContext, Boolean preview, Int32 nodeId)

   at Umbraco.Web.PublishedCache.ContextualPublishedCache`1.GetById(Boolean preview, Int32 contentId)

   at Umbraco.Web.UmbracoHelper.TypedDocumentById(Int32 id, ContextualPublishedCache cache)

   at uHelpsy.Helpers.IPublishedContentHelper.GetNode(Int32 nodeId) in D:\_PROJECTS\Personal\uHelpsy - Library\uHelpsy\Source\uHelpsy.Web\Helpers\IPublishedContentHelper.cs:line 24

   at uHelpsy.Extensions.CollectionExtensions.b__6(SearchResult x) in D:\_PROJECTS\Personal\uHelpsy - Library\uHelpsy\Source\uHelpsy.Web\Extensions\CollectionExtensions.cs:line 54

   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()

   at System.Linq.Enumerable.WhereEnumerableIterator`1.MoveNext()

   at ASP._Page_Views_Partials_uBlogsy_Landing_uBlogsyLandingListPosts_cshtml.<>c__DisplayClass2.b__1(TextWriter __razor_helper_writer) in d:\inetpub_synced\*******\Views\Partials\uBlogsy\Landing\uBlogsyLandingListPosts.cshtml:line 67

   at ASP._Page_Views_Partials_uBlogsy_Landing_uBlogsyLandingListPosts_cshtml.Execute() in d:\inetpub_synced\*******\Views\Partials\uBlogsy\Landing\uBlogsyLandingListPosts.cshtml:line 52

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()

   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)

   at StackExchange.Profiling.MVCHelpers.WrappedView.Render(ViewContext viewContext, TextWriter writer)

   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, CacheDependency cacheDependency, Nullable`1 timeout, Func`1 getCacheItem, Object syncLock)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, CacheDependency cacheDependency, Nullable`1 timeout, Func`1 getCacheItem)

   at Umbraco.Core.Cache.HttpRuntimeCacheProvider.GetCacheItem[TT](String cacheKey, CacheItemPriority priority, CacheItemRemovedCallback refreshAction, Nullable`1 timeout, Func`1 getCacheItem)

   at Umbraco.Web.CacheHelperExtensions.CachedPartialView(CacheHelper cacheHelper, HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, String cacheKey, ViewDataDictionary viewData)

   at Umbraco.Web.HtmlHelperRenderExtensions.CachedPartial(HtmlHelper htmlHelper, String partialViewName, Object model, Int32 cachedSeconds, Boolean cacheByPage, Boolean cacheByMember, ViewDataDictionary viewData)

   at ASP._Page_Views_uBlogsyLanding_cshtml.b__2() in d:\inetpub_synced\*******\Views\uBlogsyLanding.cshtml:line 23

   at System.Web.WebPages.WebPageBase.<>c__DisplayClassb.b__9(TextWriter tw)

   at ASP._Page_Views__uBlogsyBaseBlog_cshtml.b__7() in d:\inetpub_synced\*******\Views\_uBlogsyBaseBlog.cshtml:line 35

   at System.Web.WebPages.WebPageBase.<>c__DisplayClassb.b__9(TextWriter tw)

   at ASP._Page_Views__uBlogsyBaseSite_cshtml.Execute() in d:\inetpub_synced\*******\Views\_uBlogsyBaseSite.cshtml:line 44

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()

   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()

   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)

   at System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body)

   at System.Web.WebPages.WebPageBase.PopContext()

   at System.Web.WebPages.WebPageBase.RenderSurrounding(String partialViewName, Action`1 body)

   at System.Web.WebPages.WebPageBase.PopContext()

   at StackExchange.Profiling.MVCHelpers.WrappedView.Render(ViewContext viewContext, TextWriter writer)

   at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)

   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClass1a.b__17()

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilter(IResultFilter filter, ResultExecutingContext preContext, Func`1 continuation)

   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)

   at System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName)

   at System.Web.Mvc.Controller.<>c__DisplayClass1d.b__19()

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass1.b__0()

   at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.b__3(IAsyncResult ar)

   at System.Web.Mvc.MvcHandler.<>c__DisplayClass8.b__3(IAsyncResult asyncResult)

   at System.Web.Mvc.Async.AsyncResultWrapper.<>c__DisplayClass4.b__3(IAsyncResult ar)

   at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()

   at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)