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

Lucene.Net.Store.AlreadyClosedException: this IndexReader is closed
   at Lucene.Net.Index.IndexReader.EnsureOpen() in d:\Lucene.Net\FullRepo\trunk\src\core\Index\IndexReader.cs:line 204
   at Lucene.Net.Index.DirectoryReader.DocFreq(Term t) in d:\Lucene.Net\FullRepo\trunk\src\core\Index\DirectoryReader.cs:line 833
   at Lucene.Net.Search.Similarity.IdfExplain(Term term, Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\Similarity.cs:line 584
   at Lucene.Net.Search.TermQuery.TermWeight..ctor(TermQuery enclosingInstance, Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\TermQuery.cs:line 64
   at Lucene.Net.Search.TermQuery.CreateWeight(Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\TermQuery.cs:line 200
   at Lucene.Net.Search.BooleanQuery.BooleanWeight..ctor(BooleanQuery enclosingInstance, Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\BooleanQuery.cs:line 234
   at Lucene.Net.Search.BooleanQuery.CreateWeight(Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\BooleanQuery.cs:line 450
   at Lucene.Net.Search.Query.Weight(Searcher searcher) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\Query.cs:line 97
   at Lucene.Net.Search.Searcher.Search(Query query, Filter filter, Int32 n, Sort sort) in d:\Lucene.Net\FullRepo\trunk\src\core\Search\Searcher.cs:line 57
   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, PageView pageview)
   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, ContentModule contentModule, PageView pageview, 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)