Hi

Looking at the code it seems like the problem seems to be in this section of code:

content.ApplicationId = entryRow.ApplicationId.ToString();
content.CatalogId = entryRow.CatalogId;
content.Code = entryRow.Code;
content.MetaClassId = entryRow.MetaClassId;
content.Name = entryRow.Name;
content.StartPublish = GetLocalTime(entryRow.EntryStartDate(content.Language.Name));
content.StopPublish = GetLocalTime(entryRow.EntryEndDate(content.Language.Name));
content.Categories.ContentLink = content.ContentLink;
content.Associations.ContentLink = content.ContentLink;
content.ParentEntries.ContentLink = content.ContentLink;

Which would indicate that either something on the entryRow or the content is unexpectedly null. If you turn on log4net logging on debug level for the class CatalogPropertyLoader, and have error logging on for the whole site, you should be able to find out which item it fails on. There shold be a message like "Calling LoadStaticContentProperties with parameter values: ", and the values used, just before the exception. Maybe that could give some hints as to what's the cause of this error.

Regards

Per Gunsarfs

Hi,

When the issue happens, is it consistent until you restart the app pool?

@Per - We will enable debug next time if happened (wish not!) to get more hints.

@Quan - Yes, it was consistent in all our thumbnail pages until we restarted the app pool.

So, I enabled DEBUG mode this time and I've got almost same error:

2016-08-11 08:27:23,387 [120] ERROR EPiServer.Global: 1.2.5 Unhandled exception in ASP.NET
System.NullReferenceException: Object reference not set to an instance of an object.
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.AddStaticAttributePropertyValues(CatalogEntryRow entryRow, EntryContentBase content)
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.LoadStaticContentProperties(CatalogEntryRow entryRow, CatalogItemSeoRow seoRow, VariationRow variationRow,
EntryContentBase content)
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.LoadProperties(CatalogEntryRow entryRow, CatalogItemSeoRow seoRow, VariationRow variationRow, EntryContentBase content,
MetaObjectAccessor metaObjectAccessor)
at EPiServer.Commerce.Catalog.Provider.Construction.EntryBuilder.ConstructEntries(CatalogEntryDto entryDto, IDictionary`2 versionsForUnpublishedContent, IList`1 entryNodeRelations, String
language)
at EPiServer.Commerce.Catalog.Provider.Construction.EntryBuilder.Create(IList`1 contentLinks, String language)
at EPiServer.Commerce.Catalog.Provider.CatalogContentLoader.ConstructContent(IList`1 contentLinks, Func`3 createContentFunc)
at EPiServer.Commerce.Catalog.Provider.CatalogContentLoader.LoadSpecificContentInstances(IList`1 contentLinks, String language)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.BatchLoad(IList`1 contentLinks, Func`2 dbLoader)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.LoadContents(IList`1 contentReferences, ILanguageSelector selector)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.LoadContent(ContentReference contentLink, ILanguageSelector languageSelector)
at EPiServer.Core.ContentProvider.<>c__DisplayClass114_0.<LoadContentFromCacheOrRepository>b__0()
at EPiServer.Core.OptimisticCache`1.Read(String cacheKey, ReadAndCacheObject`1 readAndCacheObject)
at EPiServer.Core.ContentProvider.LoadContentFromCacheOrRepository(ContentReference contentreference, ILanguageSelector selector)
at EPiServer.Core.ProviderPipelineImplementation.GetItem(ContentProvider provider, ContentReference contentLink, LoaderOptions loaderOptions)
at EPiServer.Core.DefaultContentLoader.TryGet[T](ContentReference contentLink, LoaderOptions loaderOptions, T& content)
at EPiServer.Web.Routing.DefaultUrlResolver.GetVirtualPathInternal(ContentReference contentLink, String language, VirtualPathArguments arguments)
at EPiServer.Commerce.Routing.RequestCacheUrlResolver.GetVirtualPathInternal(ContentReference contentLink, String language, VirtualPathArguments arguments)
at EPiServer.Web.Routing.UrlResolver.GetUrl(ContentReference contentLink, String language)
at EPiServer.Web.Mvc.Html.UrlExtensions.ContentUrl(UrlHelper urlHelper, ContentReference contentLink)
at ASP._Page_Views_Shared_Products_Details_cshtml.Execute() in ~\Views\Shared\Products\Details.cshtml:line 88
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.Mvc.ViewResultBase.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.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.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.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
System.NullReferenceException: Object reference not set to an instance of an object.
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.AddStaticAttributePropertyValues(CatalogEntryRow entryRow, EntryContentBase content)
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.LoadStaticContentProperties(CatalogEntryRow entryRow, CatalogItemSeoRow seoRow, VariationRow variationRow,
EntryContentBase content)
at EPiServer.Commerce.Catalog.Provider.Construction.CatalogPropertyLoader.LoadProperties(CatalogEntryRow entryRow, CatalogItemSeoRow seoRow, VariationRow variationRow, EntryContentBase content,
MetaObjectAccessor metaObjectAccessor)
at EPiServer.Commerce.Catalog.Provider.Construction.EntryBuilder.ConstructEntries(CatalogEntryDto entryDto, IDictionary`2 versionsForUnpublishedContent, IList`1 entryNodeRelations, String
language)
at EPiServer.Commerce.Catalog.Provider.Construction.EntryBuilder.Create(IList`1 contentLinks, String language)
at EPiServer.Commerce.Catalog.Provider.CatalogContentLoader.ConstructContent(IList`1 contentLinks, Func`3 createContentFunc)
at EPiServer.Commerce.Catalog.Provider.CatalogContentLoader.LoadSpecificContentInstances(IList`1 contentLinks, String language)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.BatchLoad(IList`1 contentLinks, Func`2 dbLoader)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.LoadContents(IList`1 contentReferences, ILanguageSelector selector)
at EPiServer.Commerce.Catalog.Provider.CatalogContentProvider.LoadContent(ContentReference contentLink, ILanguageSelector languageSelector)
at EPiServer.Core.ContentProvider.<>c__DisplayClass114_0.<LoadContentFromCacheOrRepository>b__0()
at EPiServer.Core.OptimisticCache`1.Read(String cacheKey, ReadAndCacheObject`1 readAndCacheObject)
at EPiServer.Core.ContentProvider.LoadContentFromCacheOrRepository(ContentReference contentreference, ILanguageSelector selector)
at EPiServer.Core.ProviderPipelineImplementation.GetItem(ContentProvider provider, ContentReference contentLink, LoaderOptions loaderOptions)
at EPiServer.Core.DefaultContentLoader.TryGet[T](ContentReference contentLink, LoaderOptions loaderOptions, T& content)
at EPiServer.Web.Routing.DefaultUrlResolver.GetVirtualPathInternal(ContentReference contentLink, String language, VirtualPathArguments arguments)
at EPiServer.Commerce.Routing.RequestCacheUrlResolver.GetVirtualPathInternal(ContentReference contentLink, String language, VirtualPathArguments arguments)
at EPiServer.Web.Routing.UrlResolver.GetUrl(ContentReference contentLink, String language)
at EPiServer.Web.Mvc.Html.UrlExtensions.ContentUrl(UrlHelper urlHelper, ContentReference contentLink)
at ASP._Page_Views_Shared_Products_Details_cshtml.Execute() in ~\Views\Shared\Products\Details.cshtml:line 88
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.Mvc.ViewResultBase.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.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.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.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

Apparently this line of code is causing the issue: 

if (Model.ParentProductContentLink != null)

         parentProductURL = Url.ContentUrl(Model.ParentProductContentLink.Value);   //Where ParentProductContentLink  property is of type Lazy<ContentReference>

Your feedback is highly appreciated!

Looking at the exception thrown, looks the same as in this thread. http://world.episerver.com/forum/developer-forum/Problems-and-bugs/Thread-Container/2016/9/commerce-catalog-randomly-goes-empty-until-website-restart/

Great catch @Rene. It definitely looks like that was the problem.

The solution for future visitors: Make sure your Commerce Manager, or any sites which don't have the strongly typed catalog content types to have enableModelSyncCommit = "false" in web.config:

 <episerver>     

<applicationSettings enableModelSyncCommit="false" uiUrl="~/UI/" enableScheduler="false" />   

</episerver>

You're welcome :) But actually you where the one who gave me the answer, look at the bottom of this thread ;) http://world.episerver.com/Modules/Forum/Pages/Thread.aspx?id=133442

Thanks a ton Rene and Quan!

I will give it a try.