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

Lucene.Net.Store.AlreadyClosedException: this IndexReader is closed
   at Lucene.Net.Index.IndexReader.EnsureOpen()
   at Lucene.Net.Index.DirectoryReader.DocFreq(Term t)
   at Lucene.Net.Search.Similarity.IdfExplain(Term term, Searcher searcher)
   at Lucene.Net.Search.TermQuery.TermWeight..ctor(TermQuery enclosingInstance, Searcher searcher)
   at Lucene.Net.Search.TermQuery.CreateWeight(Searcher searcher)
   at Lucene.Net.Search.BooleanQuery.BooleanWeight..ctor(BooleanQuery enclosingInstance, Searcher searcher)
   at Lucene.Net.Search.BooleanQuery.CreateWeight(Searcher searcher)
   at Lucene.Net.Search.Query.Weight(Searcher searcher)
   at Lucene.Net.Search.Searcher.Search(Query query, Filter filter, Int32 n, Sort sort)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.FillFacetFieldTerms(Facet facet, FieldDefinitionBase field, IndexReader reader, Query searchQuery, QuerySettings settings, FacetGroupResult facetsResult, IList`1 exceptions)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.FillFacetResultUsingSpecializedQuery(Facet facet, FieldDefinitionBase field, IndexReader reader, Query searchQuery, QuerySettings settings, FacetGroupResult facetsResult, IList`1 exceptions)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.DoFacetSearch(IFacetGroup facets, FieldDefinitionBase[] fields, IndexReader reader, IQuery query, QuerySettings settings, Query originalQuery, IList`1 exceptions)
   at Dynamicweb.Indexing.Lucene.LuceneIndexProvider.SearchInternal(IQuery query, QuerySettings settings)
   at Dynamicweb.Indexing.Querying.QueryService.Query(IQuery query, QuerySettings settings)
   at Dynamicweb.Ecommerce.Indexing.ProductQueryHelper.ExecuteQuery(IQuery query, QuerySettings settings)
   at Dynamicweb.Ecommerce.Indexing.ProductQueryHelper.GetProductsAutoIdsFromIndexQuery(IQuery query, ProductCatalogSettings settings, QuerySettings querySettings, IEnumerable`1& facetViewModel, IEnumerable`1& spellCheckerResult)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.RenderProductList(ProductCatalogSettings settings, QuerySettings querySettings, IQuery query, String groupId, Boolean feed)
   at Dynamicweb.Ecommerce.ProductCatalog.ProductCatalogFrontend.GetContent()
   at Dynamicweb.Frontend.Content.GetModuleOutput(Paragraph paragraph, PageView pageview)