An error occurred while attaching module (Dynamicweb.Frontend.Content)

System.NullReferenceException: Object reference not set to an instance of an object.
   at Dynamicweb.Ecommerce.Indexing.ProductQueryHelper.HandleFacetsVisibility(IQuery query, QuerySettings querySettings)
   at Dynamicweb.Ecommerce.Indexing.ProductQueryHelper.GetProductsAutoIdsFromIndexQuery(IQuery query, QuerySettings querySettings, PageView pageview, Boolean showFacetOptionsWithNoResults, IEnumerable`1& facetViewModel, IEnumerable`1& spellCheckerResult, Int32& totalProductCount)
   at Dynamicweb.Ecommerce.Indexing.ProductQueryHelper.GetProductsAutoIds(ProductCatalogSettings settings, String groupId, ContentModule contentModule, PageView pageview, QuerySettings& querySettings, IEnumerable`1& facetViewModel, IEnumerable`1& spellCheckerResult)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.RenderProductList(ProductCatalogSettings settings, String groupId, Boolean feed)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)